I think it does have both sensors, because before the factory reset they did tests and they worked. The problem begins after formatting and it was not necessary to do it because the Huawei was clean, without information from the previous person, only with a google account and that is why I wanted to start the cell phone from 0. I think it could be updated at the time factory reset to emui 10.1 and maybe this generates the error. Can be?
Is this proximity sensor related to facial recognition?
Facial recognition is always done with the camera, and on many phones there are separate proximity sensors in the bezels.
However on a P30, the front is pretty much all screen with minimal bezels, there's one small notch for the camera, and no other obvious lenses or sensors. I guess this phone is using the camera as a proximity sensor during phone calls. Why it isn't working though, no real idea, except perhaps a software problem?
I've got a Huawei Mate10 here, and that definitely has a proximity sensor in the top bezel, next to the camera. I also have a Samsung Note20 Ultra, and that's similar to the Huawei P30, it's all display, with no obvious proximity sensors, apart from the camera hole in the display.