Please use this thread going forward: Infant/Toddlers needs Declined While playing another lot | EA Forums - 12082067
This issue has been around for awhile now. It would be great if it could finally be addressed. It even happens when you hire and leave your toddler with a nanny. When the adult sims get home, the nanny isn't on the lot and the toddler's needs are often in the red and need to be cheated to prevent issues. So you are paying for your toddler to be neglected. The nanny reappears after the adult sims have been back on the lot for a little bit. That alone is annoying because sometimes it's late and I want my sims to go right to bed, but at least one of them has to hang around for a bit waiting for the nanny to show back up to be paid and dismissed.
I've been having this issue as well. If one parent leaves the lot, the other doesn't care for their infant and when both parents are at work, the infants needs aren't raised while at daycare. The only mods I have are MCCC and UI Cheats so I've been cheating the infant's needs but it would be really nice for it to work properly.
