EF does not generate foreign key association from foreign key in table

I have a table tblEvent and another table tblContact. There is a field ContactID in tblEvent that is linked by a foreign key to ContactID in tblContact. I've triple checked; the foreign key is in the database.

The Entity Framework model DOES NOT generate a navigation property and foreign key association for it as it does for the other foreign keys.

What could be different about this foreign key that EF does not generate a navigation property for it?

Thanks!