Why Siri says that X is not on my find my friends list? I asked Siri on my Mac "where is X?" and she answered: "X is not on your find my friends list".

Siri can locate this person when I'm using iPhone without any problem. I checked Is there a way to &quot;Find My Friends&quot; from the desktop, rather than iPhone? and I can see the location of this person in Messages app on my Mac. Yet Siri on Mac seems to have a problem with that. Is it a bug or a feature?
I know this is two years ago, but you have to make sure you have added their iCloud email address to their contact. Once you have done this it will work... I have just tested this (August 2019)