This still has not been fixed yet, and there’s no response, update, or fix from Blizzard.
Absolutely unbelievable. The same thing is happening to retail WoW, see here: Windowed Mode - resizing quits WoW - #35 by Doñaldtrump-faerlina
Some of the PLAYERS have actually read through the crash reports and have made more headway in identifying the issue than “small indie company” Blizzard has.