Hello ayyan1530,
Thanks for using Apple Support Communities. It sounds like you’re having trouble with auto-brightness and True Tone. We’re happy to help.
To start, make sure you’ve tried restarting your iPhone to see if the issue persists:
Restart your iPhone - Apple Support
Then, check to see if you’ve made any changes to some of the display accessibility settings. According to the article below, “Some display accessibility settings, including Invert Colors, Grayscale, and Increase Contrast, might turn off True Tone.”
Adjust the brightness on your iPhone, iPad, or iPod touch - Apple Support
Should the issue persist, try reinstalling iOS. While this shouldn’t delete any of your information, it’s a good idea to have a recent backup handy:
How to back up your iPhone, iPad, and iPod touch - Apple Support
To reinstall iOS, follow the steps in the article below, under the section labeled “Put your device in recovery mode and set it up again”:
If you can't update or restore your iPhone, iPad, or iPod touch - Apple Support
Take care.
