Chosen Solution
These symptoms can happen when the end ground pins on the touch connector get bent in too much. I have seen this several times on the iPhone 8 after numerous connecting and disconnecting of the connector. I usually pry them back out with a thin needle.
I have stopped repairing home buttons but I did find this info handy from Ben Duffy.
Try unplugging the home button connector all together. If an iPhone 7 home button cable is plugged into an iPhone 8 connector, there will be issues with touch and home button because the connectors are very slightly different. If touch works afterward, I have an idea of what might restore touch function and possibly home button function. I hope this helps!
