ARKit camera won't work 4.26.2 but will work with ARCore

I am developing an app on a Macbook Pro using Unreal Engine 4.26.2 and Xcode 12.5.1. The device I am testing the build on is an iPhone 12 (standard) running iOS 14.7. As far as I know, this version of Unreal uses ARkit 4.

I have set up face tracking and image tracking features which work on an Android phone without issue.
On iOS however, when the AR session is started I can see the camera working but none of the AR functionality works.

I have also tried applying the ARkit camera material to the camera in the engine, when this is added AR initializes but displays a pink/black screen so nothing can be seen through the camera.

Blueprint for TrailScannerPawn (the camera and image tracking functionality for the back camera):

Blueprint for GM_TrailScanner (which starts the AR session using the multiplatform ARSessionConfig for the back camera):

Blueprint for GM_Filters_iOS (which starts the AR session using ARSessionConfig for the face filters using front camera):

Blueprint for BP_Filters Actor (used for face tracking on the front camera):

NOTE: This code runs perfectly on Android where the only difference is ARCoreSessionConfig is used for GM_Filters (which has it’s own separate GM)