Change Target Help!

Current Status of the Month before my son started school!

After I edit/change the weekly target.

My son and daughter have different weekly daycare amounts and I've had it like that for forever. Well now my son started school this week, and the daycare amount is a lotttt less. When I change the weekly target, it says that I've fully spent for the month, but I just needed to pay that last full week.

Any advice?