Rear camera not working

Customers phone came in with camera issues. Black screen when opening any camera and not allowing to change to front camera.

After the cameras were reset and cache was clear it is still not working.

Only things I haven't tried is factory reset and new parts but this has happened on different Android devices where the camera will only work with 3rd party apps.

3rd party apps do not work on this device.

Everything I read says the same thing and I have done everything. I am running of solutions and need some advice on what to try next.