No collision at all. Nothing has hit the tub.
It has gotten slowly worse over the last several months. Very gradual. I have been meaning to get back to the dealer to have them take a look, but honestly am dreading the response. My fear is that the dealer will blame our contractor that did the deck work, and the contractor will of course deny that his work wasn't level, etc.
We had all this done at the same time - the pool build, and the concrete deck was done and the pad for the spa was poured specifically for the dimensions of the spa. And I stressed to the crew that it HAD to be level. I really don't think it's the concrete. They did a beautiful job. (In my non-concrete-professional opinion.)
I have searched and searched online for what may have caused this and can't find anything. At this point I am REALLY hoping Bullfrog stands behind their product - because somebody had to be taking a serious coffee break when they made this particular tub!