So the iPhone won't sync, or the phone will not scan the QR code?
Saying the phone won't sync indicates it has connected just can't update the devices and timers.
If it asks to scan the QR code and fails then it is a issue with the camera and most likely a setting in permissions.
I don't have an iPhone but would think the permission settings for the Wi-Fi app to access the camera would be in the Wi-Fi permissions not the camera.
The developer can't seem to recreate the sync issue with these phones so that suggests they have the wi-fi app and phone connecting.
I'll attempt to get a setup step by step for the new IOS.
I had pushed and continue to push for an alternate initial conection setup(without using the QR code)