Anyone know why after cancelling a reservation (on hold) the seats I had picked are not showing as available like the 10 times previously I did this?

I am holding a international full fare J reservation and every three days I cancel it after first making sure the same flights and price is available (because there is no way to actually rserve full fare J and pay for it say 3 dyas BEFORE you fly) .

Today I did my three day routine and the seats I had picked are all still showing as taken - I really doubt in the 30 seconds it took that all 4 legs had the same seat taken by another.