ServiceNPC will continue to appear after canceling service

I got this bug too, where nannies keep showing up on my lot despite cancelling/sack them they keep showing up staying for a long period or just occasionally stay for the time the parent is away. It is a suprise for how long the nanny stays. Eventually after like 3 or so times to sack them they stop showing up and then I get a new baby for a new gen and all of a sudden it occurs again as soon as I hire a nanny. It has been going one for months, so far my sim money is not the issue to sack them, but it is annoying after a while.