These exact issues are absolutely happening to me too.
My sim had her infant a few days prior to the recent update and when I opened my game on the 12th to play like I do every single day, I was trying to care for my new infant because hunger was super low, along with sleep being super low, and infant wouldn't stop crying.
I was giving mom sim actions to preform to breastfeed infant, try new foods, anything to feed the baby, tried put infant to sleep, comfort infant, change infant diaper...NOTHING.. I noticed that the queues I've given her were just dropping away automatically and quickly, and she'd start her own autonomous queue and walk away. Tried canceling those out and giving actions again, dropped away again. I was like wow ok so she just doesn't want to care for the infant anymore lol?
Also, I was able to finally get mom sim to pick up her infant, she would just put the baby right back down on the floor and walk away from the crying infant. I got on to play tonight and was able to get mom to finally just hold her baby but the baby was just hanging on the moms side like magically floating there while both of my mom sims arms were at her sides, as if she's just standing doing nothing, but she definitely was not actually holding her infant as normal. I looked at my husband and said something is wrong with my game, it's completely broken and everything was fine when I played the day before.
I hope this helps and fingers crossed it's fixed soon!