synoim If you bought the phone rencetly it is normal it the first weeks that the battery drains fast. I had in the first days the same issue and in some days in 2h and 30min. of screen time usage the battery went at the 50% but after 2 weeks the battery now easily overcomes the 10h of screen usage.
This is way the battery is calibrating itself and it could take some days or few weeks.
Battery in the first days
Battery now
p.s. it also depends how you use it, and u need to deactivate some settings that could drain fast the battery like the background of some app (like Instagram, Tik Took) ecc. ecc.
