Problems with Prezi Next, You currently offline

I use Prezi Next one year, I am really excited about the new ideas, but… It isn’t working! Everytime I am trying to edit a Prezi the cloud-icon gives a pop up telling me that I am offline. I am not offline, I tried this on different wifi-connections (including one with 100mb/s d/u).
Adblockers already switched off but still doesn’t work((

A post was merged into an existing topic: Firewall-related issues and how to resolve them