As child account, how to receive shortcut from another child account shared as file to people who know me iOS 18.5?

as child account B from same organiser, I need help to open shortcut in folder shared by another child account A; shortcut is sharable to people who know A.

From file app of B, comparison of file information is identical to file app of A.

Error message is “This shortcut cannot be opened because it was shared by someone who is not in your contacts.”

why is A who is in my contact list and email communication still not in my contacts?