ive run into this problem as well.
although im not sure what triggers it
from my expirence the only time it happens is when i go back and forth using ctrl+z a lot of times it eventually glitches.
but ive almost never been able to fix it, im usually lucky and can undo past where it started or reload the scene file.
cant tell you how to manually fix it other than be careful and save a lot.
if your scared its gonna happen again, maybe try convert to polys, then duplicate the object and delete the old one and work with the new fresh one
First year 3D Grad