Mak- It COULD be the screen protector, but it’s more about brightness, flickering and contrast.
I had that happened to me as well, so before removing the screen protector try the following:
- Turn brightness to 100%;
- Disable “Extra-dim” feature;
- Clean the screen (smudges could be an issue);
- Try tilting the phone or keeping it more far ahead instead of keeping it flat;
- Turn on light mode;
Brightness to 100% and light mode actually worked for me. I have Nothing (3a) Pro as well and a screen protector. Keep me updated man