Hotspot visibility in virtual tour for VR headset

I am creating virtual tour for VR headset in Unity - I create sphere and fill it with panoramic photo as material. For every sphere I create hotspots to switch to another scene after looking at it. I was testing it with Oculus Rift DK2. The sphere was visible, but the hotspots were visible all - for all scenes, but I need to see just hotspot for the current scene [1]. Anyone has idea hot to do it? Maybe something with transparency of spheres, but I saw just hotspots, not other spheres, so I think that sphere transparency is ok.

[https://i.imgur.com/F3S9C8w.png] - here you see also other scenes, in VR headset there are only hotspots, the spheres are not visible. This is right, but about hotspots - I need to see just that one for actual sphere, not all.

I was creating virtual tour according to this tutorial: https://tutorialsforvr.com/creating-virtual-tour-app-in-vr-using-unity/ ; you can see there also script for hotspots.

Thank you for all comments.