Why doesn't RLS automatically flow in certain bidirectional situations?

Question

I have Depo table that has 1:M relation to FactSales.

BridgeOrders table has 1:M (bidirectional) relation with FactSales and 1:M (bidirectional) relation with FactCharges.

I have RLS On Depo table. The RLS flows to the FactSales but not to the BridgeOrder and Fact charges unless I enable the apply security in both directional setting on the relation between BridgeOrders and FactSales.

However, in a completely different scenario, say I apply RLS on the BridgeOrders table instead, then the RLS flows into both the FactSales and FactCharges.

Why is it that the 1st scenario needs the setting enabled whereas the 2nd scenario just works even though both scenarios have bidirectional relationships?

Answer 1

Security flows with the direction of the relationship, from the one to the many.