Hi Cristi,
Can you try to replicate this issue from your side: just run the example spatial-anchor.js and it will throw a read access violation on holographic.anchors.enumerateAnchors
Now here is the kicker, it only throws this access violation issue on release mode (no issues on debug).
VS V15.7.3
I tried it on a HoloLens with Windows V 17134.1011 & Windows V 17686.1003
Thanks