OVR Plugin failure for detection space / importing Room-Data into Unity

(NOT a duplicate post)

Someone else posted the same issue on  the meta community "get help" forum. The user said he thinks installing "Vive business streaming software" caused the issue to manifest, but I do not / never have installed that, so I believe there is a deeper underlying issue here.

Trying to run the MR samples via Link results in this error, and the room scene / objects aren't materializing at all. The PassthroughRelighting demo character immediately falls through the world if you move him at all.

(yes, I set up the room scene before starting link)

[OVRPlugin] [XRCMD][failure] [XR_ERROR_HANDLE_INVALID]: xrLocateSpace(*(XrSpace*)space, baseSpace, ToXrTime(GetTimeInSeconds()), &spaceLocation), arvr\projects\integrations\OVRPlugin\Src\Util\CompositorOpenXR.cpp:11831 (arvr\projects\integrations\OVRPlugin\Src\Util\CompositorOpenXR.h:302)
UnityEngine.Debug:LogWarning (object)
OVRManager:OVRPluginLogCallback (OVRPlugin/LogLevel,intptr,int) (at ./Library/PackageCache/com.meta.xr.sdk.core@60.0.0/Scripts/OVRManager.cs:1984)
OVRPlugin:TryLocateSpace (ulong,OVRPlugin/TrackingOrigin,OVRPlugin/Posef&,OVRPlugin/SpaceLocationFlags&) (at ./Library/PackageCache/com.meta.xr.sdk.core@60.0.0/Scripts/OVRPlugin.cs:10180)
OVRLocatable:TryGetSceneAnchorPose (OVRLocatable/TrackingSpacePose&) (at ./Library/PackageCache/com.meta.xr.sdk.core@60.0.0/Scripts/OVRAnchor/OVRAnchorComponents/OVRLocatable.cs:170)
Meta.XR.MRUtilityKit.MRUK/<LoadSceneFromDevice>d__31:MoveNext () (at ./Library/PackageCache/com.meta.xr.mrutilitykit@60.0.0/Core/Scripts/MRUK.cs:368)
System.Runtime.CompilerServices.AsyncMethodBuilderCore/MoveNextRunner:Run ()
OVRTask`1<bool>:SetResult (bool) (at ./Library/PackageCache/com.meta.xr.sdk.core@60.0.0/Scripts/Util/Async/OVRTask.cs:216)
OVRManager:UpdateHMDEvents () (at ./Library/PackageCache/com.meta.xr.sdk.core@60.0.0/Scripts/OVRManager.cs:2767)
OVRManager:Update () (at ./Library/PackageCache/com.meta.xr.sdk.core@60.0.0/Scripts/OVRManager.cs:2723)