When at the connecting screen after launching from battle.net launcher it tries to connect then says “ERROR You were disconnected from the server.” After pressing OK, it tries to go to the login screen, but the circle just spins until I get the same error again. If I switch away from US to any other region it connects.
Update: I can connect with a VPN. I believe Blizzard DDoS protection is blocking IPs outside of US even though US realm isn’t only for US servers.