touchID not working after screen replacement on idevice

Hi,

I've performed several screen replacement on iphone 6s, iphone 8 and ipadmini4 and often happens that touchID doesn't work or in case of iphone 8 home button doesn't work.

I could not exclude I've damaged the cable or contacts during switch of home button between screens (still have to find the way to remove ipadmini 4 lcd without damage).

But, in most general terms, there:

1. There are procedures to "reset" the home button (I suppose the button has to be somehow recognised by the screen since it's attached to it)
2. Any suggested testing tools for home button or lcd? (Could the problems be caused by low quality lcd?)

Best regards.