Disconnects; [Forewarned is Forearmed]
Have you tried skipping the cutscene (while awaiting a potential ‘fix’)?
Good luck.
Also, https://www.pingplotter.com/fix-your-network is a good guide to tracking down network issues. While this may or may not be a network problem, it’s a good start to eliminate that possibility.
You could also try using the `-clientport` argument with 80 or 443 for the client, and see if that helps. Some ISP “smart” filtering for torrents, etc, apparently throttles GW2 connections and causes pain, but is bypassed with that setting.