Unexpected Disconnection in the Middle of the Maven Fight

Bug Report ID: #4010660762

I was doing a Maven's Writ, and right after the first memory game, after getting Maven down to ~0hp again, I got kicked out to login screen with an "An unexpected disconnection occurred."

The same thing happens every time I try to back into the Absence of Mercy portal. Had a friend test it, same thing happens to him. So it doesn't seem to be a client-specific issue.