Ok, I should've just posted my answer earlier. So you've damaged some stuff while doing your repair. The power button, which is connected to the volume/mute, which you'll have to remove the battery and the logic board. It's a pretty big repair. Youve also likely damaged the front camera flex assembly. Not that big of a job. I mean you should check that and make sure you properly seated the connections. But likely you'll have to order new a new one

iPhone 6 Power Button Cable Assembly Replacement

iPhone 6 Front-Facing Camera and Sensor Cable Replacement

iPhone 6 Front Camera and Sensor Cable

iPhone 6 Power Button Cable and Bracket