iOS 18 issues with Intune - Guided Access App Unavailable

I don't know if you solved this, or if the cause for your problems are the same, but this is how I did.

Because the phone was pre-enrolled I could Wipe it. At first it didn't work, but the next morning the device was clean for setup. I also created a new enrollment profile and assigned the phone, the day before. The reason was that someone figured out that old profiles didn't work out with ios 18.x. There might be a new setting that blocks the process and thus the enrollment. So after new enrollment the phone was OK and had used the new profile.

I think it is the anti-theft-feature that is the culprit. So a new life cycle step is to create new enrollment profiles when new major versions roll out.

I've got the exact same problem, but with Iphone 16 with IOS 18.1. I've got major issues with the IOS 18 phones and I was lucky only one of 3 locked up, the others never enrolled correctly. Going to Apple store tomorrow.

Are you trying to put an app in Guided Access or Single App Mode?

Yes, the enrollment require Intune login at the beginning.