I found the fix! I had the same problem after screen replacement. My home button, front camera, and sound did not work. I tried buying a new ribbon and still no luck. I tried pushing harder on the connection of the camera ribbon and still the same issue. Finally I realized I had plugged it in upside down. Be careful it will click either way you plug it in. The ribbon should be going downwards when it’s plugged in, not toward the top of the phone. Simple mistake but the phone will assemble either way you plug it in. Good luck!