Ghost mount can't fly in northrend in end-game zones

Hi there, lvl 80 - when in zones of northrend that have a ghost mount when dead, such as Icrecrown, Storm Peaks etc, the gryphon mount can't fly, only run.

I have flying (150%) & cold weather purchased. I can fly when alive, but I've been unable to obtain my corpse a few times now, sometimes unstucking online but ten having to take ress sickness to continue to play.

Its not about what flying skill you have,
its just a bug that happens alot, and there is 2 methods to fix it :
1 - use the auto-unstuck ingame (will teleport you back to the graveyard + has high chance to fix the gryphon)
2 - logout to characters list then login .