I'm currently having the same issue as well, but for entirely different reasons. I had been sitting for a few hours to try and get my clothing and armors to match the BodySlide settings that I worked on, but also my game is moderately (heavily to some) modified with quite a few naughty mods. Things used to work before, but like a river, time flows and history repeats, and I'm having issues again, nude body being one thing, certain armors and cloths making the breasts 2X larger and with anti-gravity features, and certain armors and cloths giving the breasts N64 Lara Croft style breasts. It's a combination of load order, potentially conflicting mods ( which I haven't noticed any issues ), FNIS being a pain, BodySlide not doing a complete job, and ultimately SKSE being wonky. Seeing this post was made back in 2019, I'm sure the OP has fixed it long by now, but gladly giving my issues and potential causes for the issues in the first place.