anyone experienced massive battery drain during sleep?

I bought Descent MK2s last week.

I have been using fenix 6s pro for over a year, so everyting is mostly same (except slightly lower battery time). Obviously, the settings (HR, pulse Ox, watch face) are also similar

Normally, my sleep tracking would drain around 10% battery with my fenix, and was also the case with descent mk2s for a week.

but yesterday, 80% of battery dropped during sleep (which never happened with fenix 6s).

Interestingly, my friend who also bought descent mk2s (he was using forerunner 945 before),  also experienced battery drain during (his actually turned off with 0 battery) 2 days ago.

We both did not experience massive battery drain during the daytime (it's been only a week, so not completely sure if tis issue is limited to sleep)

Im wondering there is potentially a bug with new descent mk2s's firmware that may occasionally cause massive battery drain during sleep tracking?

I'll obviously have to observe for some time to see wether this is a once happening or a repeatable issue, but im curious if other have experienced similar problems.

I see this forum is named MK2/Mk2s not MK2s, but as there doesnt seem to be a seperate mk2s forum, i wrote it here