iPhone 7 front camera not working on apps after screen replacement

I had just my screen fixed , it was a full assembly when replaced. My front and back camera works perfect on my regular camera. But as soon as I FaceTime or video call the front camera is completely black but the back camera is fine. It does the same when I try to use the front camera on Facebook, messenger, or instagram. It automatically closes my Snapchat out due to it being on my front camera when I open it. I’ve tried resetting settings, restarting my phone, and deleting and reinstalling my apps. Does anyone know why it could be doing it? How do I fix it?