In the existing unity program, it was performed using the pass-through of quest. The pass-through was performed well in Unity.
When I tried again after 2 weeks, passthrough is not working in Unity. I didn't change anything, I checked the settings again, but the passthrough doesn't work. The reason is that there is someone who knows, so please help
I checked the settings again and tried to run passthrough in the new Unity program, but it didn't work.
I ran into the same issue with Unity v2021.3.22f1. What seems to have worked was exiting Quest Link mode, turning passthrough off then on again, and then enabling Quest Link mode again before playing the Unity scene. I'm not sure why this works as I still get this error in my console:
"Warning-XR Device was switched during runtime with overlays still enabled. When doing so, all overlays constructed with the previous XR device must first be disabled. UnityEngine.Debug:LogError (object) OVROverlay:LateUpdate () (at Assets/Oculus/VR/Scripts/OVROverlay.cs:1107)"
If that doesn't help and you updated your Unity version recently, you might want to revert to an older version or upgrade to a newer one. You've probably already done it but might help to run through these steps again: https://developer.oculus.com/documentation/unity/unity-passthrough/