I added multiple models to my viewer and had issues with hiding one of the models. Despite clicking on the eye icon the models are still visible. I believe I had a similar issue in the past with objects. In case you need more input than that happy to help
you are right and I’m right … on your server it works (latest version though 2.21.3 pre) … on ours it does not (latest available one 2.21.2). I will send you the videolinks with pm. Maybe it goes away with the next server version. Let’s see.