FYI: I was also using the normal enchanter for that area to apply the three buffs when Cedric presumably/finally vanished after wandering away. The item I was enchanting at the other enchanter vanished too as I was taking it out of the enchanting slot. It was not on the ground. Not sure if this ties in anywhere, but thought I'd mention it.

The item lost was of no consequence. In fact, I could try it next time to see if it happens again.

Also, if anyone is inclined to test out the mods I currently use, I have them gathered in a collection. As far as I know, that's all of them. I'll have to make sure it's set to public.

I still couldn't reproduce this behaviour, but will try again this evening. In the meantime, I made a post about this problem in Runic's GUTS-help-forum. Maybe someone there has an idea why the mob wander's off despite its "cannot wander"-option being set to "true".

EDIT: I set the OCCUPIESNODE-Option as suggested, which didn't work either. What did though, was setting his movement-speeds to 0 (walk and run). I enchanted multiple items since then, waited for a few minutes, logged out and in, enchanted and waited again, and he didn't vanish once. I hope it's fixed now, but it's still a very peculiar behaviour which is certainly not expected when you're explicitly telling a unit to stay put via a number of options...

For what it's worth..and perhaps I should have mentioned this in case it was important:

When he wandered, there was no walking animation, he just seemed to slide his way off before he phased out of existence. If it happens again, I'll try experimenting with only my required mods running (Xev's Pets and Synergies).

I noticed that too, maybe it's because this particular troll mesh doesn't have a walking-animation. I've never actually seen it in-game, just in a testing-layout in guts. I would appreciate it, if you could report it if you run into this bug again, but for now it seems to have been fixed with my last changes.