Weird rectangle around buttons in apps

[FrK]

Since yesterday I have a weird rectangle on buttons in apps on my iphone (check screenshots). It’s in multiple apps and it looks like some accessibility feature but I can’t find anything I might have turned on.

Someone got an idea?

 

[Nermal]

Try Settings/Accessibility/Display & Text Size/Button Shapes.

 

[FrK]

I did. It’s turned off. That option changes other buttons (like ‘back’ in the upper left cornet).

 

[FrK]

Still don’t know what I turned on but I reset my settings and it’s gone. So the issue is resolved.