Player crash when using flameblast

If I am in a group with someone, and I use flameblast on one side of the map and they are on the other side, they will crash to desktop and I won't. This has been confirmed multiple times.
Playing as bloodmage
Lots of area effect

Forgot to mention this occurs when doing fully charged blasts. Didnt seem to occur on patial charged flameblasts

Can confirm that I've experienced this as well from the other side - my partner plays flameblast, and if they're far enough away from me (more than a screen length or two), as soon as they flameblast mobs, I instant crash. None of their other abilities trigger it, and it doesn't happen if they're close to me.

Can confirm, having the same issue in my group