I was running Bedim easy mode today and my surge of awareness aoe warlock buff caused the tank to crash every time i used it.
Is this a known bug issue and is it only for Bedim instance?
No this is not a real bug. I have cleared Bedim a couple times now with my warlock in the party and have not seen this duplicated. However you are talking about Bedim one of the most lagggtastic instances to date and any extra player effects can send you to back to the desktop.