Bug Worldspace UI not always responding on IOS (works fine on Android)

Just flagging this issue up here and wanted to know if I was alone.

Using AR Foundation on IOS/Android, I have a prefab spawned in AR by an Image Marker which has a worldspace Canvas UI with buttons on it. On Android it works fine but on IOS the buttons are intermittently responding and don't always click.

I actually made this project using the Unity ARFoundation samples repository and used a sample scene for image tracking. Nothing fancy going on, I have extensive experience with AR projects and have made sure I have an event system/standalone input component.

I have reported this issue here:
(Case 1291989) [UI][AR Foundation] Worldspace UI buttons work fine on Android but intermittently on IOS while in AR

 

I have investigated further and this issue is directly caused by Graphic Raycaster components on screen space Canvas gameobjects interfering with worldspace UI graphic raycasters on IOS only, on Android I can have as many Screen Space canvas + graphic raycasters in the scene as I like and Worldspace UI buttons work fine. I believe this is a platform specific bug.

This was bad practice of the AR Foundation Demos team also as they have a 'Guidance Overlay' UI template which has a Graphic Raycaster on it which was the direct cause of this issue on IOS when I was investigating this issue in their other scenes. I have notified the AR F Demos team of this here:
https://github.com/Unity-Technologies/arfoundation-demos/issues/35