Smart thermostat reverts to schedule even when off
I have a Smart Thermostat which has a bunch of schedules programmed via the app. However, I've set Manual Control to Off and 'Active until ended by a user'. Every few days, I realise my heating is on, and checking the app, this manual control is cancelled and it's back to the previous schedule. Nobody else has control via the app. All geofenching is off. Nobody else is changing the physical thermostat settings. I'm super confused as to how this is happening. It is connected via Home Kit and also Alexa but again I'm not commanding any changes. Are there any logs which can be checked to work out who - or what - is changing these settings?
How I leave it:
What it resets itself to: