Why does my iPhone do this? - 3

My phone will be at full brightness and suddenly it adjusts down a level without transition, so the dim is very obvious. I open the settings and it claims the phone is still at full brightness even though i saw it dim. And no, my auto-adjust feature is turned off. Why is my phone doing this?

I assume it's just a glitch then. Try turning your phone on and off, and see if there's a software update available. Otherwise, take it to an Apple store for support help.