Hi
Maybe a hint for users, or a hint for developers for a bug... ?
Trying around with MQTT (to get it work together with FHEM).
As in my earlier post written in I feel unsure about how to read the documentation regarding MQTT output control.
So I tried around, back and forth - with different topics and payloads.
So, here my issue:
Shelly 4PM MQTT seems not very robust regarding JSON payload.
After trying a while MQTT got unstable. E.g. MQTT status didn't react on on/off commands even from the Shelly's website anymore (didn't show switch:X status anymore). Also, after a while sometimes it showed MQTT topic online=false.
Trying reboot the device by website really did a reboot - could see it at website and Shelly. But, MQTT did not recover. Only sometimes it showed topics online=true and switch:X update after looong time.
Meanwhile, all other my ~40 MQTT devices ran as usual. No issue of the MQTT broker.
And no issue with the Shelly 4PM website.
Only a power cycle seems to have the Shelly recovered to fully operational MQTT.
Currently my Shelly 4PM is working again. Hopefully it stays this way... 
I don't exactly remember the payloads which lead to the Shelly's behaviour.
Here are some which I tried on shelly-xxx/rpc:
- Exchanged all double quotes with single quotes in JSON data.
- Accidently mixed up JSON data (maybe missed some quotes, accidently exchanged colons by equal signs, ...)
- Trying on other topics (e.g. shelly-xxx/command/switch:0 on)
Best regards
Torsten
