I'm having a new issue with this as well. I've played through the SV storyline a few times and had no recurring problems after defeated the Mother. This time I chose to resurrect her and befriend her, full friendship bar and set the weirdness to the lowest level: some possessed Sims and the bizarre plants in their bud stage. Creeping vines are stage 3 I think (if not then stage 2) but I moved my family to another town and now there are vines in the plumbing. I'm not a fan of them and not happy they've shown up. ?
Being on a PS4 means no mods to fix it. ?