Sims become muscular for no reason

Same issue on xbox

Do you have "Business and Hobbies" pack? Does your sim have the mystery perk "mental muscle"? As I know that just gardening and having this mystery perk will have your sim go full body builder body. 

Hey. I’m just noticing that my sims are randomly becoming muscular, too. They’ll literally go to bed and wake up doing the animation where they lose or gain weight and the sim will just pack on muscle out of nowhere. I play on PC. I don’t have the Businesses and Hobbies pack or any other EP after Horse Ranch. I don’t have vampires, fairies or werewolves either as an FYI. My sims were vacationing in Mt. Komo when I noticed the issue after a few sim days of being there. 

This didn't become a thing for me until recently. I just loaded into a save I've been playing the new pack in and my sims are muscular compared to what I adjusted them back to before saving then exiting game. Not sure if it's the new skill, but the only sim who I had practiced it repeatedly was my male sim (though I haven't been doing that since maxing his skill out). I also have Businesses and Hobbies, but none of my sims have mental muscle special skill, so I don't know why they keep beefing up when none of them are working out to the extent that they'd gain muscle.

I'm on PC/EA App and no mods/cc as well.

I just had this happen in my save. The whole household plus the butler and roommates went max muscle. I thought it might be the new sword skill but only one of my Sims practiced this regularly. 

This is happening to all my sims after the royalty pack. The stay over guests and even the butler is buff lol 

Make sure to upvote this post. It's a really annoying bug. I hope they fix it soon. 

My sims keep getting muscular for no reason. I change them back with cas full edit mode cheat but by the next day they are buff again. I have checked the mental muscle perk and removed it, but it keeps happening.
I have noticed it has begun to happen to other sims in the world. I don't have any cc installed.