I installed Graphene OS Android 13 (no update from 12) and from time to time anything is draining my battery very fast. When analyzing it with a battery monitoring app, I found out, that the phone does not enter deep sleep mode.
After rebooting the phone (sometimes more than one reboot necessary) I can see that deep sleep mode is entered when the display is off. In this state the phone last about 3-4 days!
I couldn't isolate the problem to a specific app yet, but somehow I suspect the google framework in combination with the google camera app. Which camera app are you using?