Using the Harvard NPC, I get FA for 2 kids in college, but not 1 kid in college. I also checked Columbia, Dartmouth, Penn, MIT, Stanford, and Yale NPCs which all return FA for both 1 kid in college and 2 kids in college.
I’m not sure why Harvard is worse in this scenario. Harvard seems to have recently increased expectations for parental contributions from savings/investments. The Harvard calc is expecting contributions for assets above $50k, when previously contributions started at $200k. The scholarship for $300k income also seems worse than I remember. Perhaps there were changes after the federal funding clashes.
Different Ivy+ colleges have different FA calculations. Among Ivies, Princeton is usually the best, and Brown is usually worst or near worst.