I am so confused.....I was under the assumption that they could NOT move on paths whatsoever.
I had a perfectly open spot for one of my villagers and she bulldozed a few path patterns and trees.

I thought I understood because everything was working so well but I was mistaken?
Can someone exxplain to me what happened? I invited Fauna via Campsite

my understanding is that villagers are just significantly less likely to move onto paths, but it is still possible and you should still plot reset just incase. I've also heard that there are sometimes areas that villagers are less likely to move to for whatever reason even if there's enough room for them, but I can't confirm if that's true or not.

Have you switched to the Welcome Amiibo update yet? If so, are there any other spots for that villager to move? The only reason I'd think they'd move onto a path is that there is no 3x3 plot in town without a path or PWP on it.

I own Welcome Amiibo and I have 3x3 spots open. It's been working pretty well until now.
I have two spots available for a villager move in.

The only time another villager plopped their home on paths was with Joey but I thought that was because he came via void.

Hmmm, interesting. I'll try opening up even more places for them to plop their house to see. It's odd though since the places I have open have been used by previous villagers.

If anyone else has ideas or knowledge about this please continue to post so I can learn more about this conundrum.