Your SSQA is not designed correctly. I have this setup on my tractor. The only way
it should be able to separate is to lift up. Mine won't lift up unless I release the lock handles which is how to detach it. I can lift the front of the tractor right off the ground with the bucket. Something is not right with your setup.
It sounds like whoever fabbed your QA attachment forgot the tapered pins that drive through rectangular holes in the bottom of the mounting plate. Did your fab shop make the mounting plate from scratch or did they (or you) purchase a full blank plate? Your setup should look similar to this (note the red handles).
I recently purchased a TPH adapter for my skid steer. I could not make one for the same price