iPhone bootloop

Hi, my iphone xs max switches off as soon as it is unplugged but when it is plugged in it is stuck in a boot loop, when i try connect the usb to my computer it just doesnt boot, and when it is unplugged it doesnt boot too.

When I try to "hard reset" or "force restart" it brings me to a screen of support.apple.com/iphone/ or something like that and when I unplug it to plug it into a computer it just switches off and it refuses to show any sign of life including the apple logo, even when it is not plugged to anything it refuses to boot at all, but when it is plugged in it will be stuck on a boot loop ranging from 7-8 seconds per apple logo.

Any help will be really appreciated as I am really stressing about this :pray_tone3:

N/B: Screen and battery were replaced today.