iPhone XR will charge but wont connect to computer

Hey, so I bought an iPhone XR. It has a black line going through the middle of the screen, so I assumed all it needed was a screen replacement. The person I bought this from, told me it has a password and just needed restored in iTunes. Which I was fine with. But, it won’t connect to any computer. It will charge perfectly fine, but won’t connect to my Macbook, PC, or Mac Mini. I tried it with a new charging port and that, unfortunately, didn’t fix the issue. It does, however, boot up when turned off then plugged into the computer, but it doesn’t connect beyond that. I have no idea what could be going on with it. If it’s a board-level repair I can get that fixed, but need to know what needs repaired on the motherboard first. It also says it has been disabled for 1 minute every time I turn it on and only is really disabled for like a few seconds. Wondering if the internal clock is messed up or something. This phone also had been opened and some screws were missing. If anyone has any idea what could be wrong, please help me out.