Touch ID working fine with old screen but not with the new one

I bought a new screen replacement for my iPad mini 4 Wi-Fi only version. The replacement was flawless, except for the Touch ID. It wasn't working. When I saw the error I was like “well it looks like I broke the home button flex cable”. But then I tested it by removing the new screen and putting back the old one and Touch ID was working fine again with the broken screen. I'm confused. What could it be?

For clarification: the new screen did not come with a new home button. I carefully transferred the home button from the old screen to the new one. Touch ID didn't work.

I then installed the old screen and transfered back the home button. Touch ID works fine. I went back and forth between the two screens multiple times transferring the home button and every single time, Touch ID works fine with the old screen but not with the new one.

I suspect there's an issue with the home button connection in the new screen. Any ideas?