Wiser Schneider WV704R0A0902 - Unusual behaviour?

I am working down my zigbee journey, and have now come across another issue which I am struggling to explain.

I have a Wiser Schieder TRV connected through zigbee2mqtt, and everything is working as expected. HA identified the device and integrated it without any issues, generating a card on the default screen showing the current temperature, and allowing me to set the target temperature. Last night I set the temperature to 17°C, but when I checked this morning it was back on 20 °C. Strange I thought. I have checked all the MQTT messages I can find, and there isn’t any sign of retained messages causing this. I have reset the target to 17°C, and I see the message being published with this number. But it is still reset after some time. I have extended the logs now for zigbee2mqtt to see if there is a specific time this happens.

Have any of you seen this behaviour, and could possibly give me some hints about where to look?

Many thanks!

I’m tinkering about with using iTRV in one of the rooms directly via MQTT. I don’t want room to demand for heat, just get heat if boiler is on. It seems to be working as expected but when I look at history it’s all weird
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This sounds as similar thing, but in my case even though set point seems to be jumping between 18C and 25C this doesn’t seem to affect demand (valve remains 100% open as expected)