Illustrator CC 22.0.1 This has happened occasionally in the past few versions.
I'll create an object with the pen tool, and close the object. When I zoom to make modifications on the path I sometimes see a path shoot off to the right at ~315° from one of the anchor points and it looks like the path connecting two anchor points isn't there. As I move it around or zoom out it'll disappear, but if I move back it comes back. Editing the object isn't affected, but it is highly visually distracting. Attached video file illustrates.