I have the same issue.
Got a family of vampires and had a vampire toddler. Aged her up and for both parents, she is showing her toddler trait.
I tried "Get to Know" and seems you can't use "Detect Personality" vampire power on family members.
Don't know if this is the same issue with other sims if you change traits in CAS that the traits never update correctly (meaning still shows old traits but might have the new ones) in the relationship panel.
I think I know what caused this issue. This probably because the toddlers was interacting with random people other than their families. What I did was deleting their relationship with those random people BUT DO NOT THE RELATIONSHIP WITH THEIR FAMILY MEMBER, because it will delete the parents/children/siblings relationship (For my case I’m using MC Command but if you dont use that I think there’s official cheat for that), saved and quit the game, go back in, once you’re back in game edit the family whos having this issue from CAS in the neighborhood (without any cheats on) do nothing inside, then select OK. Now go to your household and see for yourself! I tried this twice and both working with this method. Hope this helps!
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