Brightness keeps changing

[abracadabra1980]

Weird or just unlucky; my last two iPhones have had their own personal al idea of brightness and just changed when they feel like it. I've been through the settings on the phone with an Apple tech guy yesterday and he toggled something off, (auto brightness) and it's still doing it. Very annoying.

It's to do with the lighting in the room, so if it's a dark room it'll light up, go outside and it'll dim. Auto brightness should fix it though so unsure

Thanks for the input.