University course progress suddenly gone

@Trismagistos I tried loading the eldest one of this set in, and it is one from before the previous term ended - and before Boy Sim changed schools. Girl Sim's university information is there and accurate, but his is still completely gone. Even though he's standing in his school's soccer uniform from practice.

I copied my entire saves folder and pasted a copy into my backup saves folder before I did any meddling with them.

I mean, I suppose I'm only losing three credits worth of progress, since Boy Sim had only done one term, but I am just at a loss as to the cause, and why only he's been this affected.