Bug Depth texture enabled in URP with ARKit scene creates black background

I'm trying to get volumetric lights working by Kronnect, but the lights require me to have Depth texture enabled in the URP Asset settings, this unfortunately creates a black background when trying to detect a plane on my iPad Pro. I already have the seen set up with the ARbackground in the Forward Render... so not sure what is going on. When disabling the depth texture the camera feed works fine. I have tried it in 2020.2.2 and the most recent Beta release of unity 2021.1.0b7 but still problematic with the volumetric lights.
If anyone knows why this might be happening or how to fix it , I'd appreciate it.

 

some more info, when running debug while the iPad is running I get the following error, the depth texture is not enabled but I stilll get a black screen now:
Camera "AR Camera" has a non-identity transform (position = (1.8, 1.0, 0.5), rotation = (0.1, -0.7, 0.1, 0.6)). The camera's local position and rotation will be overwritten by the XR device.

UnityEngine.DebugLogHandler:Internal_Log(LogType, LogOption, String, Object)

UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])

UnityEngine.Logger:Log(LogType, Object)

UnityEngine.Debug:LogWarning(Object)

UnityEngine.XR.ARFoundation.ARSessionOrigin:Awake()


2021-02-24 17:31:44.985162+0000 Scale[1399:590290] UnityARKit: Updating ARSession configuration with <ARWorldTrackingConfiguration: 0x28115eaa0 worldAlignment=Gravity lightEstimation=Disabled frameSemantics=None videoFormat=<ARVideoFormat: 0x2806e2440 imageResolution=(1920, 1440) framesPerSecond=(60)> autoFocus=Enabled environmentTexturing=None wantsHDREnvironmentTextures=Enabled planeDetection=None collaboration=Disabled userFaceTracking=Disabled sceneReconstruction=None appClipCodeTracking=Disabled>

2021-02-24 17:31:45.781331+0000 Scale[1399:590511] Compiler failed to build request

2021-02-24 17:31:45.782240+0000 Scale[1399:590511] Compiler failed to build request

Metal: Error creating pipeline state (Unlit/ARKitBackground): depthAttachmentPixelFormat is not valid and shader writes to depth

(null)-> applicationWillResignActive()

-> applicationDidEnterBackground()

 

ah it turns out that it was not a problem with Kronnect, if you have Depth of Field enabled with the post processing on the URP side with the AR Sessions Camera then you get black screen, bit annoying that i can't have some depth of field, but it is ok for now without

 

For anyone still having issues with this, the black background may be caused by an older version of AR Foundation (my project had version 4.1.1 installed when the bug appeared).

Updating AR Foundation to version 4.2.0 fixed it for me