Update connectivity check solution for uri not set (#24183)

source/more-info/unsupported/connectivity_check.markdown

@@ -10,8 +10,41 @@ Without this check you will face an increased number of errors and performance i
 
 ## The solution
 
-From the host shell execute the following command to re-enable Network Manager's connectivity check:
+From the host shell, first execute the following:
+
+```sh
+busctl get-property org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.NetworkManager ConnectivityCheckAvailable
+```
+
+### Output is `b true`
+
+You just need to re-enable connectivity checks by executing this command:
 
 ```sh
 busctl set-property org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.NetworkManager ConnectivityCheckEnabled b true
 ```
+
+It may take a bit for the message to go away as all checks are scheduled on timers. You can force it to recheck immediately by executing the following commands:
+
+```sh
+ha host reload
+ha resolution healthcheck
+```
+
+### Output is `b false`
+
+You need to set the connectivity uri in Network Manager's config. You can do this by adding the following to `/etc/NetworkManager/NetworkManager.conf`:
+
+```txt
+[connectivity]
+uri=http://checkonline.home-assistant.io/online.txt
+interval=600
+```
+
+Afterwards you will need to restart NetworkManager by either rebooting the host or executing this command:
+
+```sh
+systemctl restart NetworkManager
+```
+
+As mentioned above, the checks are on timers so the message may not go away immediately unless you force an immediate re-check. If you continue to see the message after a while or after forcing a re-check then start over at the top of this solution. You may need to separately enable the check now that it is available.