I'll provide a personal anecdote to explain this one because I am unsure of the technical reasons for it.
One time I was running across the Niben Bay using a spell that increases speed and maximum fatigue and allows for walking on water. I was sprinting, so my current fatigue was quite low. The spell wore off and I entered a ragdoll state, so I was unable to move. In this case I was able to fast travel, but fast travel did not allow me to move once again. I did not make a note of whether I was standing or on the ground after fast travelling. I reloaded my last save before I crossed the lake and continued playing, being more careful not to let my fatigue run out at the same time as the spell.
I later experienced two additional problems that I did not realize were related. The first, if I entered a loading door at the same time the spell wore off while my fatigue was low then I would get stuck in the ragdoll state again. It is possible that this glitch is unrelated, but I'm not sure that it is anymore. The next, if I am ever ragdolled while in play (every situation I have found except when going through load doors) I will teleport to the same coordinates where I ragdolled on the lake previously. I initially experienced this when being paralyzed by an enemy inside of a cave. Given the narrow area I was in, I had thought I simply clipped out of bounds at the time. Later on, I was paralyzed again and "clipped out of bounds", but I was in a flat open (interior) area, so I was confused. Finally, there were a few circumstances where I died. Dying in interiors causes me to "clip out of bounds" like when I am paralyzed, but on two occasions I died while outdoors and was teleported back to the Niben Bay, my corpse floating on the water.
Any time I am teleported back to the Niben Bay I lose the ability to open menus, so I am unable to load a save like I did previously. I have to Alt+F4 out of the game.