The fix is a lot easier than you think
Mine wasn’t completely unresponsive. It would highlight the button I click, but wouldn’t click it unless I double tapped after it was highlighted.
This I assume. Is problem you’re having since I would describe it the same way. If so, here’s how to fix it…
Turn your phone on and keep swiping up until your passcode pops up (If it doesn’t pop up try triple tapping the screen or the swipe up bar at the bottom of the screen)
Tap the first number of your password, it will highlight the number. Then double click on the same number and it will fill out the first number of your code
Then do that for all the rest. All the buttons on your phone will act the same. Click to highlight, then double click to have the button respond
Go into setting and search VoiceOver, again double click after it highlights, then turn it off. After that, you’re all set.
That should fix the issue, it fixed mine. Hopefully this helps