TRV Showing Incorrect Temperature

I woke up a few days ago with the heat very high in the main room. The thermostat was reading 17 degrees even though the room was about 25. I tried resetting by removing the batteries but had the same issue. I contacted support and did not get a response but I suspect they did a remote reset because I had a strange error in the app and then it was working again.

Today I woke up with the opposite problem and the thermostat is reading 22.1 even though the temperature is only 17.8. Notice the graph below, yesterday the temperature got stuck at 22.1 and doesn't fluctuate at all.

I imagine the unit is faulty and I need to get it replaced but I don't want to return the pack of three. Has anyone faced a similar issue? Or any tips on how to get an answer from support? I still don't have a reply to my message from four days ago.