isIdleTimerDisabled not working in iOS 12

Question

Prior to iOS 12 using isIdleTimerDisabled has stopped our app from going to sleep, but ever since iOS 12 this no longer seems to work.

Is this a bug with iOS 12 or am I doing something wrong here?

Answer 1

This is for sure a bug and apparently Apple fixed it is iOS 12.1.1. You will see a new option under the Guided Access called Mirror Display Auto-Lock. Turn this on. Then go to Settings -> Display and Brightness -> Auto-Lock -> Never. This should fix it.

Here is a link to the most active thread about this issue on the Apple Forums.