I'm actually aware of this issue, it has happened to me before while testing the mod, but don't know how to fix it. I think it's because of how this mods places walls after loading the surface. I think it's less likely to happen if you are walking more slowly, were you wearing power armor with exoskeletons?
With the way I plan to generate surfaces in the future, this doesn't happen, because the surface is generated completely before the player character is placed on it.