Those certain circumstances I’ve experienced a couple of days in a row before this update. I thought that this somehow related to the issue with my Kyivstar eSIM.

Recently, Kyivstar was attacked by russian hackers, and they are destroyed core network software that caused loss of service for all customer base. I thought that battery drain can be caused by eSIM seeking the network and can’t find it.

https://www.macrumors.com/2023/12/20/ios-17-2-1-release-notes-battery-drain-fix/