Safari 15 has NSURLSession Websocket enabled by default.  This causes media to fail to connect and the following message is displayed:



To join Challo via Safari 15 please disable the NSURLSession Websocket feature.  To disable please complete the following on your relevant platform. 


MacOS:


Selecting from the menu bar Safari > Preferences > Advanced and check Show Develop menu in menu bar

  

Select Develop > Experimental Features > NSURLSession WebSocket to remove the checkbox


Restart Safari


iOS:


Settings > Safari > Advanced > Experimental Features and move the toggle switch off for NSURLSession Websocket