Hi overnight battery drain

hi friends , ios 14 i running time i never face this problem,

after updates to ios 15, first three days i face this issues, midnight and daytime also some times,

if apps using my battery if reduced battery means , i agree its my battery problem,

BUT

here see screenshot , no apps runs in front or background in iphone , but still battery falling down ,

apps setting background app refresh always OFF, from day one,