@Karritz I hate using the constrain floor elevation cheat because I always end up messing up the houses really bad so I doubt it's that. Got another baby glitch today, finally tried out the strollers...
https://i.imgur.com/OHpMhAU.jpg
https://i.imgur.com/6FZlZl9.jpg
Happened around the same spot with both twins...
On a side note, immediately after the glitch the sim carries the baby normally for a couple steps with an extremely disgusted look on their face with no "disgusted" moodlet or anything.