diff --git a/wled00/FX_fcn.cpp b/wled00/FX_fcn.cpp
index d4a1345bb..6c28b3e76 100644
--- a/wled00/FX_fcn.cpp
+++ b/wled00/FX_fcn.cpp
@@ -1089,14 +1089,11 @@ void WS2812FX::deserializeMap(uint8_t n) {
     return;
   }
 
-#ifdef WLED_USE_DYNAMIC_JSON
+  #ifdef WLED_USE_DYNAMIC_JSON
   DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-#else
-  if (!requestJSONBufferLock()) {
-    DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-    return;
-  }
-#endif
+  #else
+  if (!requestJSONBufferLock(5)) return;
+  #endif
 
   DEBUG_PRINT(F("Reading LED map from "));
   DEBUG_PRINTLN(fileName);
diff --git a/wled00/cfg.cpp b/wled00/cfg.cpp
index 5fda92073..8d77b6bb8 100644
--- a/wled00/cfg.cpp
+++ b/wled00/cfg.cpp
@@ -425,14 +425,11 @@ void deserializeConfigFromFS() {
     return;
   }
 
-#ifdef WLED_USE_DYNAMIC_JSON
+  #ifdef WLED_USE_DYNAMIC_JSON
   DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-#else
-  if (!requestJSONBufferLock()) {
-    DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-    return;
-  }
-#endif
+  #else
+  if (!requestJSONBufferLock(1)) return;
+  #endif
 
   DEBUG_PRINTLN(F("Reading settings from /cfg.json..."));
 
@@ -456,14 +453,11 @@ void serializeConfig() {
 
   DEBUG_PRINTLN(F("Writing settings to /cfg.json..."));
 
-#ifdef WLED_USE_DYNAMIC_JSON
+  #ifdef WLED_USE_DYNAMIC_JSON
   DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-#else
-  if (!requestJSONBufferLock()) {
-    DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-    return;
-  }
-#endif
+  #else
+  if (!requestJSONBufferLock(2)) return;
+  #endif
 
   JsonArray rev = doc.createNestedArray("rev");
   rev.add(1); //major settings revision
@@ -777,14 +771,11 @@ void serializeConfig() {
 bool deserializeConfigSec() {
   DEBUG_PRINTLN(F("Reading settings from /wsec.json..."));
 
-#ifdef WLED_USE_DYNAMIC_JSON
+  #ifdef WLED_USE_DYNAMIC_JSON
   DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-#else
-  if (!requestJSONBufferLock()) {
-    DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-    return false;
-  }
-#endif
+  #else
+  if (!requestJSONBufferLock(3)) return false;
+  #endif
 
   bool success = readObjectFromFile("/wsec.json", nullptr, &doc);
   if (!success) {
@@ -829,14 +820,11 @@ bool deserializeConfigSec() {
 void serializeConfigSec() {
   DEBUG_PRINTLN(F("Writing settings to /wsec.json..."));
 
-#ifdef WLED_USE_DYNAMIC_JSON
+  #ifdef WLED_USE_DYNAMIC_JSON
   DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-#else
-  if (!requestJSONBufferLock()) {
-    DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-    return;
-  }
-#endif
+  #else
+  if (!requestJSONBufferLock(4)) return;
+  #endif
 
   JsonObject nw = doc.createNestedObject("nw");
 
diff --git a/wled00/data/index.js b/wled00/data/index.js
index fe311ca50..9bef5dbbf 100644
--- a/wled00/data/index.js
+++ b/wled00/data/index.js
@@ -1066,6 +1066,7 @@ function updateSelectedFx()
 	var parent = gId('fxlist');
 	var selEffectInput = parent.querySelector(`input[name="fx"][value="${selectedFx}"]`);
 	if (selEffectInput) selEffectInput.checked = true;
+console.log(selEffectInput);
 
 	var selElement = parent.querySelector('.selected');
 	if (selElement) selElement.classList.remove('selected');
@@ -1106,7 +1107,7 @@ function makeWS() {
 		jsonTimeout = null;
 		lastUpdate = new Date();
 		clearErrorToast();
-	  	gId('connind').style.backgroundColor = "var(--c-l)";
+		gId('connind').style.backgroundColor = "var(--c-l)";
 		// json object should contain json.info AND json.state (but may not)
 		var i = json.info;
 		if (i) {
diff --git a/wled00/fcn_declare.h b/wled00/fcn_declare.h
index 3edccb5f8..2b81199f9 100644
--- a/wled00/fcn_declare.h
+++ b/wled00/fcn_declare.h
@@ -272,7 +272,7 @@ void sappends(char stype, const char* key, char* val);
 void prepareHostname(char* hostname);
 void _setRandomColor(bool _sec, bool fromButton);
 bool isAsterisksOnly(const char* str, byte maxLen);
-bool requestJSONBufferLock();
+bool requestJSONBufferLock(uint8_t module=255);
 void releaseJSONBufferLock();
 
 //wled_eeprom.cpp
diff --git a/wled00/ir.cpp b/wled00/ir.cpp
index 0cdca96a3..f3b6355e0 100644
--- a/wled00/ir.cpp
+++ b/wled00/ir.cpp
@@ -576,14 +576,11 @@ void decodeIRJson(uint32_t code)
   JsonObject jsonCmdObj;
 
   DEBUG_PRINTLN(F("IR JSON buffer requested."));
-#ifdef WLED_USE_DYNAMIC_JSON
+  #ifdef WLED_USE_DYNAMIC_JSON
   DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-#else
-  if (!requestJSONBufferLock()) {
-    DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-    return;
-  }
-#endif
+  #else
+  if (!requestJSONBufferLock(6)) return;
+  #endif
 
   sprintf_P(objKey, PSTR("\"0x%lX\":"), (unsigned long)code);
 
diff --git a/wled00/json.cpp b/wled00/json.cpp
index f130d4096..5c28916bf 100644
--- a/wled00/json.cpp
+++ b/wled00/json.cpp
@@ -917,15 +917,12 @@ void serveJson(AsyncWebServerRequest* request)
     return;
   }
 
-#ifdef WLED_USE_DYNAMIC_JSON
+  #ifdef WLED_USE_DYNAMIC_JSON
   AsyncJsonResponse* response = new AsyncJsonResponse(JSON_BUFFER_SIZE);
-#else
-  if (!requestJSONBufferLock()) {
-    DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-    return;
-  }
+  #else
+  if (!requestJSONBufferLock(7)) return;
   AsyncJsonResponse *response = new AsyncJsonResponse(&doc);
-#endif
+  #endif
 
   JsonObject lDoc = response->getRoot();
 
diff --git a/wled00/mqtt.cpp b/wled00/mqtt.cpp
index 3b608df0c..9ef3a22fb 100644
--- a/wled00/mqtt.cpp
+++ b/wled00/mqtt.cpp
@@ -92,12 +92,9 @@ void onMqttMessage(char* topic, char* payload, AsyncMqttClientMessageProperties
   } else if (strcmp_P(topic, PSTR("/api")) == 0) {
     DEBUG_PRINTLN(F("MQTT JSON buffer requested."));
     #ifdef WLED_USE_DYNAMIC_JSON
-      DynamicJsonDocument doc(JSON_BUFFER_SIZE);
+    DynamicJsonDocument doc(JSON_BUFFER_SIZE);
     #else
-      if (!requestJSONBufferLock()) {
-        DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-        return;
-      }
+    if (!requestJSONBufferLock(8)) return;
     #endif
     if (payload[0] == '{') { //JSON API
       deserializeJson(doc, payloadStr);
diff --git a/wled00/presets.cpp b/wled00/presets.cpp
index 580dc44aa..114f593db 100644
--- a/wled00/presets.cpp
+++ b/wled00/presets.cpp
@@ -22,14 +22,11 @@ bool applyPreset(byte index, byte callMode)
     deserializeState(fdo, callMode, index);
   } else {
     DEBUG_PRINTLN(F("Apply preset JSON buffer requested."));
-  #ifdef WLED_USE_DYNAMIC_JSON
+    #ifdef WLED_USE_DYNAMIC_JSON
     DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-  #else
-    if (!requestJSONBufferLock()) {
-      DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-      return false;
-    }
-  #endif
+    #else
+    if (!requestJSONBufferLock(9)) return false;
+    #endif
 
     errorFlag = readObjectFromFileUsingId(filename, index, &doc) ? ERR_NONE : ERR_FS_PLOAD;
     JsonObject fdo = doc.as<JsonObject>();
@@ -57,14 +54,11 @@ void savePreset(byte index, bool persist, const char* pname, JsonObject saveobj)
 
   if (!fileDoc) {
     DEBUG_PRINTLN(F("Save preset JSON buffer requested."));
-  #ifdef WLED_USE_DYNAMIC_JSON
+    #ifdef WLED_USE_DYNAMIC_JSON
     DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-  #else
-    if (!requestJSONBufferLock()) {
-      DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-      return;
-    }
-  #endif
+    #else
+    if (!requestJSONBufferLock(10)) return;
+    #endif
 
     sObj = doc.to<JsonObject>();
     if (pname) sObj["n"] = pname;
diff --git a/wled00/set.cpp b/wled00/set.cpp
index e97974ee8..a47a27e77 100644
--- a/wled00/set.cpp
+++ b/wled00/set.cpp
@@ -415,14 +415,11 @@ void handleSettingsSet(AsyncWebServerRequest *request, byte subPage)
   //USERMODS
   if (subPage == 8)
   {
-  #ifdef WLED_USE_DYNAMIC_JSON
+    #ifdef WLED_USE_DYNAMIC_JSON
     DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-  #else
-    if (!requestJSONBufferLock()) {
-      DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-      return;
-    }
-  #endif
+    #else
+    if (!requestJSONBufferLock(11)) return;
+    #endif
 
     JsonObject um = doc.createNestedObject("um");
 
diff --git a/wled00/util.cpp b/wled00/util.cpp
index e9af648ea..281887f85 100644
--- a/wled00/util.cpp
+++ b/wled00/util.cpp
@@ -131,15 +131,20 @@ bool isAsterisksOnly(const char* str, byte maxLen)
 }
 
 
-bool requestJSONBufferLock()
+bool requestJSONBufferLock(uint8_t module)
 {
   unsigned long now = millis();
 
   while (jsonBufferLock && millis()-now < 1000) delay(1); // wait for a second for buffer lock
 
-  if (millis()-now >= 1000) return false; // waiting time-outed
+  if (millis()-now >= 1000) {
+    DEBUG_PRINT(F("ERROR: Locking JSON buffer failed! ("));
+    DEBUG_PRINT(jsonBufferLock);
+    DEBUG_PRINTLN(")");
+    return false; // waiting time-outed
+  }
 
-  jsonBufferLock = true;
+  jsonBufferLock = module ? module : 255;
   fileDoc = &doc;  // used for applying presets (presets.cpp)
   doc.clear();
   return true;
@@ -148,8 +153,11 @@ bool requestJSONBufferLock()
 
 void releaseJSONBufferLock()
 {
-#ifndef WLED_USE_DYNAMIC_JSON
+  DEBUG_PRINT(F("JSON buffer released. ("));
+  DEBUG_PRINT(jsonBufferLock);
+  DEBUG_PRINTLN(")");
   fileDoc = nullptr;
-  jsonBufferLock = false;
-#endif
+  #ifndef WLED_USE_DYNAMIC_JSON
+  jsonBufferLock = 0;
+  #endif
 }
diff --git a/wled00/wled.h b/wled00/wled.h
index d21dff4ed..47c20e9ad 100644
--- a/wled00/wled.h
+++ b/wled00/wled.h
@@ -606,7 +606,7 @@ WLED_GLOBAL UsermodManager usermods _INIT(UsermodManager());
 #ifndef WLED_USE_DYNAMIC_JSON
 WLED_GLOBAL StaticJsonDocument<JSON_BUFFER_SIZE> doc;
 #endif
-WLED_GLOBAL volatile bool jsonBufferLock _INIT(false);
+WLED_GLOBAL volatile uint8_t jsonBufferLock _INIT(0);
 
 // enable additional debug output
 #ifdef WLED_DEBUG
diff --git a/wled00/wled_eeprom.cpp b/wled00/wled_eeprom.cpp
index 03d0a8067..691ea81de 100644
--- a/wled00/wled_eeprom.cpp
+++ b/wled00/wled_eeprom.cpp
@@ -382,14 +382,11 @@ void deEEP() {
   
   DEBUG_PRINTLN(F("Preset file not found, attempting to load from EEPROM"));
   DEBUGFS_PRINTLN(F("Allocating saving buffer for dEEP"));
-#ifdef WLED_USE_DYNAMIC_JSON
+  #ifdef WLED_USE_DYNAMIC_JSON
   DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-#else
-  if (!requestJSONBufferLock()) {
-    DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-    return;
-  }
-#endif
+  #else
+  if (!requestJSONBufferLock(12)) return;
+  #endif
 
   JsonObject sObj = doc.to<JsonObject>();
   sObj.createNestedObject("0");
@@ -469,6 +466,7 @@ void deEEP() {
   File f = WLED_FS.open("/presets.json", "w");
   if (!f) {
     errorFlag = ERR_FS_GENERAL;
+    releaseJSONBufferLock();
     return;
   }
   serializeJson(doc, f);
diff --git a/wled00/wled_serial.cpp b/wled00/wled_serial.cpp
index 5e250818d..c7d9a9968 100644
--- a/wled00/wled_serial.cpp
+++ b/wled00/wled_serial.cpp
@@ -44,14 +44,11 @@ void handleSerial()
         else if (next == '{') { //JSON API
           bool verboseResponse = false;
           DEBUG_PRINTLN(F("Serial JSON buffer requested."));
-        #ifdef WLED_USE_DYNAMIC_JSON
+          #ifdef WLED_USE_DYNAMIC_JSON
           DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-        #else
-          if (!requestJSONBufferLock()) {
-            DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-            return;
-          }
-        #endif
+          #else
+          if (!requestJSONBufferLock(13)) return;
+          #endif
           Serial.setTimeout(100);
           DeserializationError error = deserializeJson(doc, Serial);
           if (error) {
diff --git a/wled00/wled_server.cpp b/wled00/wled_server.cpp
index 07ff2107b..cb3da0aae 100644
--- a/wled00/wled_server.cpp
+++ b/wled00/wled_server.cpp
@@ -111,19 +111,18 @@ void initServer()
     bool isConfig = false;
     { //scope JsonDocument so it releases its buffer
       DEBUG_PRINTLN(F("HTTP JSON buffer requested."));
-    #ifdef WLED_USE_DYNAMIC_JSON
+      #ifdef WLED_USE_DYNAMIC_JSON
       DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-    #else
-      if (!requestJSONBufferLock()) {
-        DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-        return;
-      }
-    #endif
+      #else
+      if (!requestJSONBufferLock(14)) return;
+      #endif
 
       DeserializationError error = deserializeJson(doc, (uint8_t*)(request->_tempObject));
       JsonObject root = doc.as<JsonObject>();
       if (error || root.isNull()) {
-        request->send(400, "application/json", F("{\"error\":9}")); return;
+        releaseJSONBufferLock();
+        request->send(400, "application/json", F("{\"error\":9}"));
+        return;
       }
       const String& url = request->url();
       isConfig = url.indexOf("cfg") > -1;
diff --git a/wled00/ws.cpp b/wled00/ws.cpp
index 5722a3284..9457d9774 100644
--- a/wled00/ws.cpp
+++ b/wled00/ws.cpp
@@ -36,15 +36,12 @@ void wsEvent(AsyncWebSocket * server, AsyncWebSocketClient * client, AwsEventTyp
         }
         bool verboseResponse = false;
         { //scope JsonDocument so it releases its buffer
-        DEBUG_PRINTLN(F("WS JSON receive buffer requested."));
-        #ifdef WLED_USE_DYNAMIC_JSON
+          DEBUG_PRINTLN(F("WS JSON receive buffer requested."));
+          #ifdef WLED_USE_DYNAMIC_JSON
           DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-        #else
-          if (!requestJSONBufferLock()) {
-            DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-            return;
-          }
-        #endif
+          #else
+          if (!requestJSONBufferLock(15)) return;
+          #endif
 
           DeserializationError error = deserializeJson(doc, data, len);
           JsonObject root = doc.as<JsonObject>();
@@ -116,15 +113,12 @@ void sendDataWs(AsyncWebSocketClient * client)
   AsyncWebSocketMessageBuffer * buffer;
 
   { //scope JsonDocument so it releases its buffer
-  DEBUG_PRINTLN(F("WS JSON send buffer requested."));
-  #ifdef WLED_USE_DYNAMIC_JSON
+    DEBUG_PRINTLN(F("WS JSON send buffer requested."));
+    #ifdef WLED_USE_DYNAMIC_JSON
     DynamicJsonDocument doc(JSON_BUFFER_SIZE);
-  #else
-    if (!requestJSONBufferLock()) {
-      DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-      return;
-    }
-  #endif
+    #else
+    if (!requestJSONBufferLock(16)) return;
+    #endif
 
     JsonObject state = doc.createNestedObject("state");
     serializeState(state);
diff --git a/wled00/xml.cpp b/wled00/xml.cpp
index a1bca6c7f..0a59cf270 100644
--- a/wled00/xml.cpp
+++ b/wled00/xml.cpp
@@ -253,14 +253,11 @@ void getSettingsJS(byte subPage, char* dest)
     // add reserved and usermod pins as d.um_p array
     oappend(SET_F("d.um_p=[6,7,8,9,10,11"));
 
-  #ifdef WLED_USE_DYNAMIC_JSON
+    #ifdef WLED_USE_DYNAMIC_JSON
     DynamicJsonDocument doc(2048); // 2k is enough for usermods
-  #else
-    if (!requestJSONBufferLock()) {
-      DEBUG_PRINTLN(F("ERROR: Locking JSON buffer failed!"));
-      return;
-    }
-  #endif
+    #else
+    if (!requestJSONBufferLock(17)) return;
+    #endif
   
     JsonObject mods = doc.createNestedObject(F("um"));
     usermods.addToConfig(mods);