No audio when charging

Greetings everyone,
My s9+ got water damaged, so I decided to open it, clean it with isopropyl alcohol, dry everything and connect everything back, but now when I connect to charger speakers stops working, in adb logcat there is that it switches to null audio device, is this motherboard related or usb board replacement will fix it?
Any other idea? I wanna give this phone to my sis in 100% condition.
Thanks to everyone :)

Also worth to mentiton, since day 1 there is 1 pin missing on the FPC on the motherboard, can anyone tell what that pin is for?