replaced my iphone 12 battery

My battery health before was 77%. replaced it today at an istorm - a legit apple certified store - so i know it’s a genuine apple battery and not a gimmick.

its been 4,5 hours and my battery is draining just as fast as before. i did some research and ai told me that it can be normal bc “the phone is getting used to it” and also “there may be background apps, and icloud syncing which i bought yesterday may be using battery too” and that i have to charge it all night.

but i want to know if anyone else has experienced this, and if so what did you do? did it get better?