Found the problem. Good catch.
The problem was actually in applying minor changes to reference fields, like changing just the on Update. Then the whole foreign key got dropped and that is why it was becoming an invalid sub table and not displayed well.
So it will be solved in the next update.
Also just as note you probably never want to have only cascade on delete and not on update.
On update will probably never happen anyway, but if it does you wan to cascade it as well.
On update means - if somehow you change the primary id - the change should cascade to all related children that use that id and be changed there as well.