We've done some testing and can't seem to replicate the issue. I hope that means it is rare. Would you be able to provide some additional information to help us debug this? Any of the below that you remember could be helpful.
What platform were you playing on (Web, Windows, Linux)?
Was everything locked up, or you just couldn't control the character to move or attack? For example, could you pause or get to the tools menu? Could the enemies move?
I can see that your character was charged for the Whirlwind attack. Were you trying to activate it when this happened?
Did you just get hit when the issue started?
Thank you for reporting this bug, and any additional info you can provide.