Black video after screen replacement?

I installed a replacement screen from AliExpress for a good price. It is really excellent, but the front camera shows a black (same as blocking the lens). I can still record videos/images, but the result is just black. The workshop wants to take off the screen to inspect it, but warned there is a high risk of damaging the screen in the process.

What do you think the cause of this issue is?

The screen I bought was advertised as having a dot around the camera.

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