Screen dimming

You can disabled auto-brightness in Settings>Accessibility>Display&Text size... last option at the very bottom.

When done, restart your iphone.

If the issue still persists, check if you have a screen protector that can obstruct (interfere with) your ambient sensor (located in the notch of your X). Remove it.

Regards

Giulio

Hi, Ive had many iPads and this is a persistent issue with them all - you can switch off auto-brightness, switch off night mode,l ensuring sensors aren’t covered, makes sure its updated, switch it off and on again - nothing works, it still dims while you are using it - that has been the case for evert iPad I’ve had