Find My.app finds Devices, but no longer finds People.

This just started after a session with Apple Support Chat, in which I used Internet Settings to delete iCloud and restore it. After that, this problem appeared.

Find My still works just fine with my iPhone. It can find the person associated with an iPhone, even though that person has several devices left at home.

FindMy.app running under Sonoma 14.4.1 in my MacBook Air used to work similarly. However, after deleting iCloud and restoring iCloud, FindMy.app running under Sonoma 14.4.1 can still find devices, but not people. It simply displays "No location found".

How can we restore the association between an iPhone and a person?

--Gil