I had a similar problem with weather sensors, but it was a while ago and Domoticz has been updated since then. I was presenting temp, hum, baro. Domoticz always assumed it was a weather sensor if I presented the baro -- and the humidity wouldn't update. It didn't matter if I used separate child IDs or the same one. I really only wanted temperature and humidity, so I quit presenting the baro and the Domoticz temp/hum has always worked well. I just assumed I was doing something wrong, but your problem sounds similar. Maybe it's a Domoticz bug.