Technical Stuck in the air outside of Dalaran

[Oksmow]

Hello everyone !

I bought a character on trade system, and on this one and only character, whenever I fly (by mount or flightmaster), I'm stuck in the air and can't do nothing about it.
I can also dismount while stuck, I do not fall, the only solution to it is to ALT+F4, which is not a real solution...
I cleared cache, did a request IG with an answer from the GM saying that I have to look for it on the Bugtracker (as always), but nothing helped me.

I am asking if anyone's got this problem before and how they solved it.

Thank you, regards !

[Oksmow]

I guess I have to up my topic ?

Help ! :D