Last night I was assigned belts in a PUG, the first belt was fine, but when the raid warning came up for belt 3, I jumped in and got ported out straight away - leading to a wipe. After recovery, tried again, failed again to the same thing. I didn't want to screw up the rest of the raid so I apologised and dropped group.
So my question is: How long after the warning for Belt 3 do I jump on?