There are two separate bug reports, if I understand correctly. And a third one, if it is for a vampire. One is a teleportation issue connected with stairs.
https://answers.ea.com/t5/Bug-Reports/OPEN-Sims-not-visible-to-player-teleport-abort-interactions/td-p/10527641
One is for random teleporting and jumping around. This has apparently been going on for a long time, but got worse after the last patch.
https://answers.ea.com/t5/Bug-Reports/OPEN-Jumpy-Animations-Sims-teleport/td-p/6876628/page/14
I'm not sure if your problem falls into one of these categories, but they are some of the most mentioned issues that players are experiencing since the Cottage Living patch.
I don't believe that there is anything that can be done to fix it yet. At least, not that I have seen.
