How do you get an infant to Pull To Stand?

just what the title says, how do you get your infant to pull to stand. I think there might ge a glitch because I used to be able to make the parent sim, holding the infant, practice 'pull to stand' on a floor, and after a few times parent sets infant down, infant crawls to open chair, and pulls itself up.

i have tried this with 3 different families, different save files, one i tested with no mods installed, all the same result. whats happening now is the parent sim just stands there like an idiot holding the infant as it fusses and cries, and if you manually make them set the infant on the floor near an open chair, nothing happens. if you click 'practice standing' under activities, nothing queues up, nothing happens. you just click endlessly until the normal game glitch happens and the parent just sets the fussing infant on the floor so they can sniff the dusty floors 🙄

is this a glitch that is planning to be fixed? cause yeah i can cheat the milestone, but i like the animation of the parent watching the milestone happen and if i cheat it i miss put on that. plus, you shouldn't have to have mod and cheat just to get your infant to learn how to stand.

what is wrong with this stupid game?