[GRO] Infant/Toddler wont achieve milestones

I'm having to exit and repair my game at least once per hour because milestones stop being granted. Infant/toddler will get the "milestone" bubble in the lower left with the task, and adults/teens will stop everything to observe, but nothing happens. Eventually, if I haven't been paying attention, this causes caregivers to drop tasks to do infant/toddler related care tasks as if they have autonomy. Which is very definitely turned off, given how long my sims will also stand staring at a wall if I forget to assign them something to do. 
I didn't realize this was the cause of it taking nearly 6 or 7 in-game days for one infant achieve the roll over milestones. I was getting frustrated because omg how many tummy time sessions do they need?! Repair game and BOOM he was rolling over the sitting up before needing another nap. 
Enough stuck milestones build up that after I repair my game and load back in, the kid will achieve 3-5 milestones in quick succession. This is especially "fun" with twins.