Maybe you can try deleting the app and downloading it again!

I haven’t. In my experience the Italki support team is helpful and friendly. You should definitely try that!

If the problem persists, notify support. They'll start by telling you to clear your browser cookies and cache, so if you've already done that, you can mention it to them right away. In your case, since it's both the app and the web page, it may be an internet issue. Wifi signal, DNS resolution (whatever that is), maybe your internet service provider....

Always have a backup video platform. I use Zoom and Google Meet.

Me, but I am new to this