@Tommi_Enenkel, so sorry for the trouble and thank you so much for taking the time to report this issue.
From what I’m seeing on your screenshot, it seems you’re failing to connect to Websockets. To confirm this assumption, could you please run this test? https://connectivity-test.asana.com/
If this doesn’t help, please comment on this thread and I’ll get our Dev Team to investigate this further. And of course, if there is anything else I can help with in the meantime, please let me know, I’ll be more than happy to help!