Battery drain after a fresh factory reset

I went for a run two days ago, and noticed the screen was turning off during my run, even though AOD during activity was enabled.
After my run, I searched in settings if anything could have caused this - low battery, activity options, power saving mode, focus modes... Without success. AOD should have stayed on.

So I tried a factory reset.
After that, I checked that AOD activity behaviour was back to normal, and it was fine.

I was about to leave for a run this morning and noticed battery was down to 12%. It was near 40% yesterday.



I have NO idea where the drain comes from. No connect IQ app installed (only Battery Graph widget). The only cause I can think of is the incident detection feature which stays on after activity is stopped (even though activity mode was only triggered for a few seconds, to check AOD...) even though it was supposed to be fixed in version 11.81.

Has anyone experienced a similar battery drain ?
This is getting annoying. The software experience of the Fenix 8 is a huge disappointment.