world/hub = "Audeuro.TestHub"
world/visibility = 1
var/old_visibility = world.visibility
var/new_visibility = !old_visibility
world.visibility = new_visibility
world << "Visibility toggled from [old_visibility] to [new_visibility]"
The first bug I noticed was when I hosted it on my VPS as well as the Tibbius server, then closed out my VPS's instance. The server listing showed both servers open while the server count went down to 1, as opposed to 2. The second one is certainly directly related:
I put up my world, then toggled visibility from 1 to 0 once. It changed, as expected, and the server listing reflected that and the # servers was accurate. I then toggled it again from 0 to 1 and the server appeared again, everything was right. This is where everything started to go sort of haywire, as far as I could tell. Toggling it once more caused the # servers to drop to 0 but the server listing still showed my server, as in the screenshot. Toggling it again from 0 to 1 caused the # servers to go back up to 1. After that, changes in visibility had no visible effect.
I then took that world down to refresh the hub entry. After everything was updated accordingly, I put the server back up. This time I couldn't get changes in visibility to affect the hub entry at all, the server remained visible through thick (0) and thin (1).
I discovered this while investigating another possible bug with world.visibility itself, but the unpredictable behavior of the hub entry made it impossible to determine anything from my testing.
Additionally, I have used CTRL+F5 in Firefox every time to refresh the page in an attempt to eliminate browser caching from the problems.