iPhone 12 Pro screen randomly going dark.

Hi guys! I have an issue with my iPhone 12 Pro screen - but it was also an issue with my old iPhone XR. The screen randomly goes dark.

Currently at the moment I have auto brightness off, and never ever had it on as a matter of fact, and I leave the brightness about a quarter of the way up. But sometimes - as it did a moment ago, the screen goes very dark. For example, when that happens, pushing the toggle all the way up to the top of the brightness scale does change it but it’s very dark. And at its normal quarter way up, it’s almost as if the screen is off. The only way to solve it is to press the side key and lock the phone and then unlock it and it’s back to normal.

Sadly it isn’t something I can screen cap as it’s the screen and not the phone itself. I will endeavour to capture a video of it from another iPhone when it happens so you can see what happens.

I was wondering if anyone else knew why this happens? I was hoping that it wasn’t going to happen on my 12 Pro as it was happening on the XR but it still happens and no updates have solved this - if it is an issue that is.

Any advice would be great! Thank you and happy holidays.