Parenting Predicament Scenario

I am at the point in this scenario where my two toddler sims are close to finishing their child aspirations but as soon as they do so, they age up immediately with no time to get them to blow out candles.  I have tried getting them to complete their aspirations one at a time, during their birthday party and this works for one of them but not for the second who ages up straight after, even though blowing out candles is in their queue.  On a possibly related note, everyone at this point also seems to age up straight away even though their birthdays are not for several days.

I don't have mods and I am playing on a laptop.  Auto Age is off and Sim Lifespan is normal.