Cams not loading or they'll load but nothing will show/only audio will be heard..

When selecting a cam to view the cam will either not appear at all or it will appear for a little bit and then disappear (but you can still hear the audio). When I re-click to view their cam the audio will close. I only view like 1 or 2 cams at a time currently, so it isn’t that I’m watching too many. Not sure if it is the internet browser I’m using (Firefox) or not, but if so, is there a preferred internet browser to use for this new site?