Since their "Fix" few months ago about mounts stuck in the ground, the problem was solved for most of players, but it was even worse for me, playing in crowded map was a real nightmare since everytime I wanted to use a mount, I had to wait for 15s-20s to be able to move without the camera being stuck where I mounted (rip auric basin loot).
After seeing some people complain about it in map chat I tried ALOT, of things to find a fix.
And well, it appear that this bug occurs only when you use the Default Mounts Skins, I never bothered to buy any, so I tryed one by one, and tested it in crowded maps, and no stucks with a new appearence.
But, sometimes you'll be in a Hilarious T-pose and no Running animation from the mounts... At least, the camera will follow your character.
So yeah... You have to Pay for a skin to bypass this stuck kitten show.