I'm encountering delayed operation of scheduled tasks of some apps, like auto-exporting their config, or SMSes/contacts etc. to a file. For example, if I have it set to trigger at 6pm, sometimes it will only do it once I unlock the screen after that hour. It doesn't happen always, but sometimes triggers even as late as 2 hours late. If it didn't run when the screen is locked, it immediately runs when unlocked past the hour. If the screen was unlocked not too long before the hour, it usually works, so there seems to be some period of phone inactivity that causes apps to "hibernate".
However, similar issue never happens with Syncthing-Fork app that runs continuously, so it seems to only affect apps that don't normally work all the time but instead do something once at scheduled time.
All of affected apps already have the permission to use unrestricted battery.
What could be the problem? I have Pixel 8