Gnomes Glitch-Dancing/ Jumping around

I DO have mods, but have noticed the gnomes on a public lot kept moving around. I had just downloaded this lot from the gallery, and hadn't been on it lot, so I thought I was seeing things. Since it is the only lot I have played that has gnomes on it, I haven't noticed it again. Now I want to place gnomes on my lot and see if it occurs on a different lot.