I know there is some kind of bug with NPCs where sometimes they just reset out of the blue and spawn in all their original items but keep the current weapon they are wielding. Everything else previously in their inventory is deleted. I’ve seen this happen in my current game many times already as well as previous games (other worlds). The one type that usually does is the one who has a molotovs, flamethrower, dynamite, pipe bomb, matchbook, refillable lighter, pair of fingerless gloves, etc. Strange thing is after he resets and you take all those spawned-in items away, ‘t’ rade with him again and he spawns in all those items again minus 1 item. So eventually he stops spawning them when you ‘t’ rade with him long enough. I just delete all those items since it seems cheaty at that point.
Another bug with NPCs is they reset their sleeping schedules. Eg. You tell them to ‘sleep when they’re tired’ but then they reset to ‘stay awake.’
So yeah there are some issues with NPCs that’s why I only give them food and water and no important items to keep. Strangely enough they keep all the armor you give them after they reset.