I have the similar issue. Looking at the battery usage, it is strange that battery charge suddenly drops in 1-2 hour window when phone is not in use.It got to be some background creep. Looking usage in that time window shows
Settings using 68% and Home and Lock screen using 24% and "Recently deleted apps" using 6%, really, after an app is deleted, it is still using battery? really??
This is just ridiculous to charge phone every 5 hours and battery drains this fast when not in use. Before IOS 14.3 upgrade battery was fine. Apple, please provide a fix asap.