I have DB model with table per type inheritance.
For example, entities are A, B, C, A1, A2.
Base - A
Derived - A1, A2.
Another - B, C.
So, A has 1 to 1 association to A1 and A2.
B and C has associations(1 to many, with OnDelete action on the DB side) to A1 and A2 respectively.

**Problem**

I trying to delete record from B, so I expect that EF remove also all A1 objects which associated to current B's record.

In the end, EF remove record from B and all associated records from A1, but not from A 

Why? how fix it?