I stumbled upon a workaround today and thought it may be useful, as it allows you to continue working after syncing. Once the BIM 360 sync dialog box goes away, click the Revit icon on your taskbar so it's active, then press enter. The sync dialog box should pop up and you can cancel to continue working. I hope this helps.
I'm running the latest version of Enscape (2.8) with Revit 2020.