iPad Mini 6 screen is dark when locked for 1 second then goes bright

Hi there, my iPad mini 6 is very dim for 1 second once I touch the screen when locked, then it goes to normal brightness. It does this every time the display is off and then touched. This issue occurred in the past and Apple Support made me reset all settings which did fix the issue for a few months however, now it's happening again. It's not auto brightness or any of the standard settings you might expect. Is anyone else experiencing this? I really do not want to keep resetting all of my settings as it's a massive pain just to fix this issue temporarily.

The increase in brightness isn't as slow and gradual as auto brightness, it's more like flicking a switch and going bright. Pictures attached show the brightness level immediately after the screen or power button is pressed, then the brightness after 1 second where it goes to normal brightness.

Software is up to date with 15.2.1