iOS 15 screen brightness bug?

[Rafagon]

I just recently updated to iOS 15. I was using my phone normally and the display brightness suddenly decreased. Now I'm trying to increase the brightness (using both Control Center and the brightness setting in Settings) and the brightness only goes as high as a certain point (a little less than halfway through the slider); above that point, the screen doesn't get any brighter. So I can't achieve maximum brightness as before. In fact, like I said, I can only get to about 40% brightness.

In other words, my brightness has been capped at about 40%. The slider can go higher, but the brightness stops getting brighter at about the 40% mark.

UPDATE: I powered my phone off, then back on, and brightness control is back to normal. Nonetheless, this had never happened before, and I'd love to hear if anyone else experienced it.

UPDATE 2: It just happened again. I'm capped at 40% brightness. This is going to be annoying.

 

[Velin]

Try a fresh, clean install of iOS 15. Plug your iPhone into a Mac, and "restore" your iPhone using the Finder dialogue boxes. It's going to be a bit of work to reinstall passwords and apps, but a clean install is always the way to go with a major release.

 

[kaioshade]

Usually that happens when the phone gets to a certain temperature. Since you just updated to iOS 15, the OS re indexes all of your files. Combine that with some day to day use, and you might see temps go up, and cause the screen dimming.

I can't say with 100% certainty that is happening with your phone, but it is a thing iPhones do.

 

[Rafagon]

Usually that happens when the phone gets to a certain temperature. Since you just updated to iOS 15, the OS re indexes all of your files. Combine that with some day to day use, and you might see temps go up, and cause the screen dimming.

I can't say with 100% certainty that is happening with your phone, but it is a thing iPhones do.

This seems to be the most likely scenario. My display brightness control is back to normal. And this time I didn't have to power off the iPhone and back on.

 

[zorinlynx]

Yeah, this happens to me when I'm using GPS navigation in my car and the phone is in the sun. It's really annoying because when it's in the sun is when you need the most brightness! I suppose the phone is protecting itself though.

This has nothing to do with iOS 15; my iPhones have been doing this for years now across many iOS versions.

 

[menizzi]

Settings/Accessibility/Display and text size/Auto brightness off

 

[Rafagon]

Settings/Accessibility/Display and text size/Auto brightness off

Thank you, but the previous replies on my post helped me realize that the screen automatically dims when the phone gets too warm.