First of all, I'm a Martial Artist.
It happened to me twice, the first one I used "Quick Attack" to a mob that walked behind a tall rock, and when I dashed to him, I got bugged for several seconds, like 35 seconds, after that, I found myself falling from the sky, I think that meant I was falling since I got bugged, I was just really high.
The second time I do not remember what skill I used, but this time it was for a longer time, about 2 minutes, I tried re-logging and didn't fix anything, when I decided to definitely close the game to do something else, I noticed I was falling from the sky again.
Here's a photo of what it looks like when I'm bugged: