TouchID and Home Button not working after replacement

Hi,

I order from a seller on eBay a iPad Mini 4 LCD/Touch replacement. I saw that it has to desolder and solder again a flex that connects the home button to the assembly.

After the replacement and transfer for this flex the home button will not work, but if I solder it again to the broken one. It will work flawless. any one had encountered this issue?

I test the same procedure on 3 different replacement LCD/Touch assembly and in neither will work, only on the original broken one.

Any help will be thanked!