I did submit a ticket and this is the reply I received:
This is Game Master Nohuzupu. Thank you for contacting Blizzard Entertainment.
First, I’m sorry to hear that you’re experiencing this in the game. I can imagine how it must feel to encounter a challenge that prevents you from fully enjoying your gaming experience.
So I did some deep digging for you, let me explain what’s going on!
This error occurs after too many consecutive login attempts. It can also happen if you are suddenly disconnected from the server. Try waiting 5-10 minutes before attempting to log back in. This allows the server more time to update your account’s status.
If the situation remains the same or you have further concerns after trying the above, please report the issue on our Diablo IV Tech Support forum.
It’s been a pleasure assisting you today with your request and If there are any other questions or inquiries, please don’t hesitate to contact us anytime, we’ll be happy to assist as much as we can.
I did reply back to this letting them know that I did not try logging in too many times and I was not in game to get kicked out of it. So will keep you informed as I know more.