Dynamo is painfully slow when I'm online

Dynamo Core
Dynamo Revit

Starting Dynamo (from Revit 2019 but apparently not 2018) is excruciatingly slow when I have an internet connection. As soon as I kill the wifi connection it finishes loading and I can get started.

It also hangs for quite a while at random times. These are not complex workspaces and even happens without course material workspaces from Lynda.com (so it’s not just my newbie confused workspaces).

Any idea what might be going on?