It is a known bug… 100 % repeatable.
Character Stuck link: https://us.battle.net/support/en/help/wf/wow/586/834/submitted
Look at road… If road has a grass spot on hill and you go up or down the hill you will be disconnected.
Just go to left or right of road.
If you are going down hill you need to do the unstuck service.
If you are going up hill, just turn to left or right or go up the right side road.