Wired Broadband
Comcast Xfinity
VPN does not resolve the issue
It is affecting both retail as well as Classic.
Additional notes: Sometimes I can get logged into a character, but am booted after less than 1 minute. Other times I do not make it all the way to the game world. I always get booted with the WOW51900319 error. I was able to play consistently from about 7am EST until roughly 2pm EST today, 09/09/2019, but have not been able to log in since then.