Why won't the phone boot with a new screen?

I just had a client bring an iPhone 7 plus and it wouldn't get past the Apple screen when I replaced the screen. I tried two more screens and it still wouldn't get past the Apple screen with any of them. I let them sit for 5 or 10 minutes but it would show the apple logo, flicker like ot was going to boot them just go back to the apple logo.

I plugged the old screen in and it booted right away. I transferred the components back over to the original screen and turned it on- and it took forever to boot again but finally did! When it did, the home button would read my fingerprint but wouldn't push back like it should have.

I've done a couple hundred screen repairs so I don't think I did anything wrong. Is this a new IOS issue? Any ideas? I'm about ready to close up shop! I'm tired of Apple.