Fyi, Mario fixed the bug! I haven't had time to test it so hope it works.

Seems author released a bug fix for the AttributeError. Tried this version and now the attributeError has disappeared, but still have the same problem with 3em: 2022-08-19 18:11:08.066 Shelly varaaja: onHeartbeat called 2022-08-19 18:11:08.098 Error: Shelly varaaja: 'onHeartbeat' failed 'KeyError ...

@burnoutvmax did you find any fix? I have new install Domoticz on Ubuntu 20.04 and I have the same error as you did. My house has Shelly 1PM and also 3EM. First I tried to read 3EM but it failed. Then I tried 1PM and was a bit confused as there was no 1PM on the list, so selected PM. Similar error ...