Fix assist conversation language picker (#27764)

src/panels/config/voice-assistants/assist-pipeline-detail/assist-pipeline-detail-conversation.ts

@@ -109,15 +109,26 @@ export class AssistPipelineDetailConversation extends LitElement {
   }
 
   private _supportedLanguagesChanged(ev) {
-    if (ev.detail.value === "*") {
+    this._supportedLanguages = ev.detail.value;
+
+    if (
+      this._supportedLanguages === "*" ||
+      !this._supportedLanguages?.includes(
+        this.data?.conversation_language || ""
+      ) ||
+      !this.data?.conversation_language
+    ) {
       // wait for update of conversation_engine
       setTimeout(() => {
         const value = { ...this.data };
-        value.conversation_language = "*";
+        if (this._supportedLanguages === "*") {
+          value.conversation_language = "*";
+        } else {
+          value.conversation_language = this._supportedLanguages?.[0] ?? null;
+        }
         fireEvent(this, "value-changed", { value });
       }, 0);
     }
-    this._supportedLanguages = ev.detail.value;
   }
 
   static styles = css`

src/panels/config/voice-assistants/dialog-voice-assistant-pipeline-detail.ts

@@ -214,7 +214,7 @@ export class DialogVoiceAssistantPipelineDetail extends LitElement {
         <ha-button
           slot="primaryAction"
           @click=${this._updatePipeline}
-          .disabled=${this._submitting}
+          .loading=${this._submitting}
           dialogInitialFocus
         >
           ${this._params.pipeline?.id