Home button stopped working after repair, but Touch ID is fine?

After a screen repair, the home button stopped working after a couple days, while the Touch ID continued and continues to work.

I ordered two official Mac metal back shields with home button flex ribbons. I put a new one in and made sure the home button flex cable was seated properly to the home button flex ribbon multiple times, as well as the flex ribbon to the corresponding connector on the logic board. No luck.

After this I connected the remaining new back shield while the other one was on, while the phone was still apart and it seemed to work fine. So, i put that one on, and it didn't work. Again I made sure everything was seated properly.

Does anyone know what problem I have, as well as a solution?

I would greatly appreciate it.

My next (and current) step is to buy a new home button flex cable and replace that, to see if that solves the problem.