Why does no home button work after battery replacement?

So I replaced the battery on this black iphone 7, 32GB. It got a replacement screen some time ago, in case that matters. When I closed the iPhone back up, the home button didn’t work. Just wouldn’t click. I have another fully functioning iPhone 7 at home, so i got to testing. I took a look at the flex cables, tried another home button, even tried another display/home button combo (which was working in another phone) but the home button still wouldn’t work. I even tried another working taptic engine (even though a defective taptic engine could not really be the reason) It just doesn’t react to presses. Touch ID also doesn’t work (but i don’t get the “touch id couldn’t be activated” message!) and double tapping the home button to reach the top of the screen also doesn’t do anything. Restarting/Hard Restarting the phone also doesn’t help. The flex connectors on the logic board also don’t look damaged, i even took pictures but couldn’t see any bent pins etc. What on earth could I have damaged inside the phone that causes no home button to work?