User_id: null on events

Hello ,
I am trying to make an automation for shopping list and i want to get notified on my phone only when my wife adds and item and vice versa, seems pretty logical to me . but when i add the user_id to context of the automation it doesn’t get triggered

i did troubleshoot to see what the user_id that gets populated when the event is triggered but got surpirsed that it is null

My question is , is this by design ? or i am doing something wrong