Same as so many other users, but – hey, why not try for the 1000th time to get even the barest acknowledgment from Blizzard that they have a problem.
Nearly every time I fast travel – which could be clicking on a city on the map or hitting T for town portal – I either get a black screen followed by the disconnect error message, or I get a black screen with the UI elements visible.
Nothing new – check the many other posts here or Reddit discussions of this same issue. As far as I know the only help anyone has gotten on this is to be sent to the generic connection problems page.
Read around and you will see a wide variety of hardware configurations, attempts to turn of crossplay, etc. None of it helps.
Is Blizzard working on this? Are they aware of it? WTF knows. Their players sure don’t.