siri keeps forgetting my mother's relationship to me

I try to teach Siri that "xxxxx" is my mother. Siri says "OK - I'll remember that xxxxx is your mother". Then when I say "call mother" she says "I don't see a mother in your contact list. What is you mother's name"

every time!

Then I look at my details and I see that Siri added "xxxxx" as my manager (I do not see a father or mother option.

In the past it worked, although every now and then I needed to "remind" Siri. But now it does not work. what is wrong?