Face ID sensor pushing on the back of screen and breaking it

Hello all,

I work at a repair shop and we had an iPhone XR come back with a breakage on the LCD from the inside. Upon inspecting I saw that the Face ID unit, that is not screwed in for whatever reason, was slightly out of place, causing it to press on the back of the screen and making it break. After pushing the sensor back into place and carefully checking that it was still in the correct position before closing the phone, we gave it back to the customer. It is now two days later and the customer is here again with the same problem.

Has anyone had this same issue or can offer any solutions?

Thank you,

Justin