I also have this bug! I found a temporary work around if you have mods, and you use MCCC to select another member of the household to modify in CAS, and you change the infants outfit to another, and return to the game, it makes the bug dormant again until it is retriggered.
The bug also prevents the infant from being picked up and moved at all by the caregivers. For example, if you select the bugged infant to be placed in a highchair/crib, it will show that the adult has a routing error to move the child. Doesnt matter if the caregiver or infant selects it.
This might help you more so here's a tip since you don't need to change anything and might be a bit faster for you. Next time Just go into CAS, cancel and it should solve it issue. It seems loading screens will fix the issue until you get the pop up next time it's needed for when all adults are not on the lot.
