Radio Thermostat 3M50 issues?

Are there any known issues with radiotherm for the Radio Thermostat 3M50? I have two of these thermostats, and I have to admit that I don’t look at them with HA very often. I believe that when I first started using it 6 months or a year ago, the HA integration was working very well. However, when I checked it recently, only the First Floor thermostat was showing up. I restarted HA and now only the Second Floor thermostat is visible. I tried a couple more resets and can still only see the second floor.

(I’'m pretty sure the thermostats are OK, because they work properly with the cloud service, and they also work OK when I poll them periodically to read the temperature for another tool.)

Is there anything I should try? Or anything I can do to help debug?

I should also have mentioned that I’m NOT using autodiscovery. My config file has:

climate:
  platform: radiotherm
  host:
    - 192.168.2.44
    - 192.168.2.45