[GRO] Infant/Toddler wont achieve milestones

I have the same issue. For those experiencing this, I've found that - at least in my game - they generally stop achieving milestones if I travel to a lot outside my home lot and come back. Workaround is to change to a different active household real quick when your sim comes back home from "traveling" and then come back to the original active household. Then the infant will achieve milestones until you decide to travel again. Super annoying (and incredibly insane that this doesn't have a fix after 6+ months....but that's how the Sims team operates I guess...), but hope this helps folks.