I'm having a similar issue. I have a sim that graduated from Highschool early that I aged up into a young adult. She is the only adult sim in the household that does not have the option to apply to university. This sim is from a household that I played with in a different save file, and I had her apply to university and get accepted as a teenager in that save file, but of course she couldn't attend. I don't know if that is the reason this issue is occurring. When I placed this household in the current save file, she was a highschooler again even though I had her graduate early in the other save file and she still had the graduated early trait.
