Child not recieving milestones after completing

My child just finished learning to ride his bike and the milestone doesn't come up. I've tried following tips online, traveling to a new lot, moving the household, moving back, nothing seems to work. Other milestones (such as first tooth) seem to work okay, as far as I have got. 

Some forums have said this can happen if child has top notch traits, and mine has both top notch infant and top notch toddler.