Thanks for posting here, @Franki Chamaki - we’re checking with the Copilot teams on what could be the variety of causes for this. Will get back to you on it. 

Here's a few suggestions which might help you out @Franki Chamaki

1) Try running it on some other network. In past we have noticed that some ISPs have trouble connecting to the AWS cloudfront/s3 where these calls are hosted. Or it can happen if the network isn't stable to load these huge call files.

2) Make sure that the app is up to date. 

3) Try viewing the same call on the webapp and make sure that you have access for that call. Sometimes you might land on a call (via url) for which you don’t actually have access to. Although we’d normally show an error toast if that happens on the mobile app but there’s a chance that got missed. Low chances of this happening but still worth checking.