Are you sure you are not filtering out the results (e.g. viewing only a specific gametype)?
It is also possible that you were playing on a server that was using a specific "
DO NOT LINK[/b]) h t t p s : / / openarena . wikia . com/wiki/Mod]mod": in that case, when you leave the server and return to main menu, you are not in "baseoa" anymore, but you are still in that specific mod. And it is possible that the server browser of that mod has got some dedicated filter or some incompatibility. You can try to use "mods" menu to return back to base OpenArena, or simply quit and launch the program again.