iPhone 14 pro max screen flickers during always-on display lock-screen

so this iphone 14 pro max was dropped, screen got replaced, few days later green lines started to appear. got the screen replaced again, no lines so far but I noticed screen will flicker regularly (1/sec) during always-on display lockscreen. no problem when the phone is unlocked and on normal brightness. I'm concerned that the power supply to the screen might got damaged during the drop or during repair. any ideas?