Spatial Anchors bug: LoadUnboundAnchors returns null UUIDList

Hi,

I am struggling trying to work with Spatial Anchors and what looks like a bug. I am creating a few gameobjects in the virtual room, adding Space Anchors to them, saving the room anchors to local storage and reloading them. I save the uuid list so I can reload the objects even if I close the app and run it again. It works fine but, in some "random" situations, the LoadUnboundAnchors returns a null UUIDList as if it were no Unbound anchors to be loaded. 

When this happens I can try and try to load them but always get the same result. But... if I create a new anchor in the session and save it, then I can reload all of them.🙄 Once they are loaded I can remove all objects and anchors and reload again and works fine.

So, it looks that I cannot load correctly the saved anchors unless I have previously saved one in the same session. I know that they are correctly saved because after creating a new anchor in the empty room I reload them succesfully.

Anyone else have this problem? 

I am using Quest 2, Unity 2022.3.11, Meta XR Core 59.

The loading sequence is something like this:

OVRSpatialAnchor.LoadOptions options = new OVRSpatialAnchor.LoadOptions
{
    Timeout = 0,
    StorageLocation = OVRSpace.StorageLocation.Local,
    Uuids = GetSavedAnchorsUuids() 
};

OVRSpatialAnchor.LoadUnboundAnchors(options, _anchorSavedUUIDList =>
{ 
    if (_anchorSavedUUIDList == null)
    {
        //Debug.Log("Anchor list is null!");
        return;

    }

 ....
}