Basically, an Aeon 4-in-1 sensor is changing its functionality in HC2, the IR-sensor is classified as a thermometer in HC2.
Got similair and other weird behavior om the aeon 4-in-1 sensor, however the sensors are not very accurate, I like the concept. Device against te wall and a nice readout of the designated area. I use them on USB power and latest firmware.
I had the issue, passive IR turned into a temperature sensor or the temperature sensor is missing from the device menu in HC2. In both situations there is no special event / alarm or other trigger. Happens every few days, 4 ~ 5 days.

I guess its HC2 related because in the device tree with the slave devices the T is shown correctly (and readout)

Temperature seems to exist in slave menu.

When this happens the device becomes inacurate, movement detected when nobody is present in the room. Movement icon is shown until the device is reconfigured. Or when there is movement, nothing is detected.
Powercycle and/or reconfiguring doesn't work, all settings are factory default. The only solution is to remove and add the device again and they work for a few days. Complete useless in this setup, you can't depend on it. Got 3 sensors, and all sensors go crazy.
Got another motion sensor SP814 is battery powered and placed outside, this device is working like a charm. No false alarms, no failures (no slave devices also)