Skyrim: Special Edition XB1 - Kaidan (Modded Follower) Stuck in High Hrothgar

I had the same problem. I told him to "wait there" through pointer commands because he wouldn't stop walking in front of me during my first encounter with the Greybeards. Naturally, there's no "follow" counter-command just "Talk Kaidan", so I told him to follow me through dialogue, and he did; once. Once we were in the courtyard, he never moved again unless he was called or in combat (or if I dismissed him). So here's what I did, I dismissed him, I made a save (a permanent one, not a quicksave or an autosave), then I quit the game, disabled the mod, reloaded the game, waited 24hrs, saved the game, exited the game, re-enabled the mod, did a full system reboot, and reloaded the most recent save. His first quest should pop up immediately, and you'll find him back in the prison. A word of note, with me as soon as I opened his cell door he dropped down from his binds and wouldn't speak at all until all the Thalmor were eliminated and combat had ceased (he just ran around with his fists raised), but we worked normally after that - and has been working perfectly so far. Hope this works for you!

Kill him, load your save, kill him, load your save.

Save that game then leave the actual game.

Load that save and tell him to wait there.

Save again and then leave the actual game again.

Load it back up and tell him to follow you.

He WILL follow you!