Unofficial Skyrim Special Edition Patch

... has a lot of bad places. My follower is constantly getting stuck, so I've got to reload and walk a different path.

Platforms and steps seem to be the worst spots. There's also a room where you take the right path and they halt, you have to take the left path into the same room instead. They also run around in a different direction to meet you from time to time.

000FE682 in KilkreathRuins02 is an island. That whole hallway is joined to the rest by a single shared vertex. No way for a follower to join you as you walk toward the last trigger. Good thing you need to go back down again.

0009CB6A in KilkreathRuins03:

Most of the steps up to platforms have no navmesh, but one on the far right and rear does, so the follower runs up that stair and along the platform to be near you, but cannot get back down until you figure out that you have to walk back behind the sword pillar to encourage her to run toward you there.

Other spots have navmesh running through chairs and pots and broken tables, but stops short of wide open spaces at the front of the room. There's edge cover deeply inside walls.

Most gregiously, the navmesh runs through the back wall onto a non-existant platform. Seems like they navmeshed an old design, and never updated it after changing the room.