I cannot turn on screen sharing on my server running GNOME with a wifi hotspot.

The idea is that VNC clients connect to my server via the wifi hotspot. I need
this because the server is running at remote locations where no other networks
exist.

If I go to the GNOME Sharing preferences, I cannot turn on screen sharing. The
slider / switch just does not allow turning it on.

Observations:
- If I disable the wifi hotspot and connect my computer to an existing wifi in
my testing environment, I can turn on the screen sharing with no problems; but
I have to tell/allow GNOME Sharing to use the wifi connection for the screen
sharing.
- With the wifi hotspot enabled, GNOME Sharing does not offer to select the
hotspot wifi as a network to use for the screen sharing.