I can’t currently reproduce any disconnects and will continue to monitor. I’m now noticing MG game traffic going through the IP 137.221.96.152 from its previous of 137.221.97.120.
It does strike me as odd that you mention symptoms that haven’t been reported by anyone else - it’s possible that you were seeing the same issue as Disconnecting from the Server and unable to interact 100% with every feature of DragonFlight Expansion as all of those symptoms except for the chat issue are reported here.
I performed the same logout/login process as you, but several system restarts have been performed in the process for me, it’s followed me across multiple computers, and no data was downloaded upon restarting Battle.net for me.