Use of Home button

You might have torn apart the flex cable on the display for the home button when opening the phone, so i would try with a new display if the flex cable looks bad. If that doens’t fix the issue you might have damaged the home button itself when taking the phone apart. If you put a opening tool between the frame and display on the bottom left side there’s a chance that you got in contact with the home button flex cable and in return damaged the home button.