iPad Pro screen glitching out during repair

Hey all. First time poster, so I’m sorry if formatting is bad.

I ordered a replacement screen and digitizer from iFixit for my first-gen iPad Pro 12.9” as the original screen broke, and I’m having a little bit of trouble. Everything went fine at first with getting the original screen off, but when I plug the new screen in, I get glitchy looking visuals as well as the touch capacitor doesn’t register my inputs.

I stupidly tried to put the screen back on and even took the original screen off without originally disconnecting the battery, so I don’t know if that’s the main cause, but I suspect it. Right now, I’m trying to get the screws loose that hold in the battery cables so I can disconnect it, then I’ll try connecting the screen and turning it back on. I am having trouble with getting the screws out without stripping them, so any advice on how to get them out easier would be appreciated.

My main question though is: Is there something wrong with the screen I ordered from iFixit? Or is something else going on here that I’m not seeing? Hopefully the cause is just my blunder of not disconnecting the battery first, and if it is, would I be fine to disconnect the battery and try that?

As a side note: I have not been able to get the iPad to register the touch ID home button that I plugged into it. No reason it shouldn’t considering it’s the home button that’s paired to that specific iPad. I know, I’ve got a lot of problems, I apologize for this, as I’m not a master repairer.

Thanks for the help!

Also, here’s some photos and videos of what I’m seeing and what I’ve done so far:

Inside of the iPad:

Underside of screen and digitizer with home button:

Closer look at home button connection:

Video of the glitching effect as well as non-responsive touch: