Running iOS 15.0.1 I have found that the Photos process is constantly running in the background causing the battery to run low prematurely.
With 2h 4min Screen On and 12h 52min Screen Off, the Photos process has been running in the background for 9h 4min.
With 2h 4min Screen On and 12h 52min Screen Off, the Photos process has been running in the background for 9h 4min.