Pixel 3a screen repair did not work

Hi, I broke my Pixel 3a screen, and ordered a replacement screen from iFixit

After removing the old screen and plugging the new one in, it kind of works, but I get faint horizontal lines across half of the screen. Here’s an image I took of the phone (bad quality, don’t have a good camera on my backup phone):

This photo I found online shows the exact same problem:

Debugging:

• I’ve tried disconnecting and reconnecting the ribbon cable 3 times, it looks exactly the same each time.
• I’ve tried power cycling the device a couple of times.
• Wiggling around the cable / chips at the bottom of the screen unit has zero effect on the problem. It always looks exactly the same kind of wrong.

However, another problem I noticed is that while the screen is the right size, the ribbon cable is about 0.8mm too long. When I lay the new screen flat while plugged into the ribbon cable slot, the screen is 0.8mm offset from the bezel that it should fit inside of:

Did I get the screen unit for the wrong phone somehow? My order clearly says “Google Pixel 3a Screen”. Or is it defective? Is there anything else I can try?