Shelly TRV forgets temperatur after mode change


I have two brand-new Shelly TRV Radiator Valves. I am using the integration and set CoIoT to IP of my Home Assistant, port 5683.

Basically, everything works flawless, besides one thing.

When I change from Off mode back to Heating mode using the Climate Card, sometimes, the device forgets the temperature that was previously set. Looking at the device’s log:

There is one log entry nicht mehr verfügbar / not available. I got no idea what can cause it (can’t be wifi reception, as the access point and the valve are just a couple of meters away). But I think, as soon as this not available happens, the temperature is forgotten.

Can anyone shed some light on it and possibly even know of how to fix that issue?

Thanks a lot!