I'll confess. Mind you we've owned this thing for 5 years.
She had the seat adjusted to the highest position. Usually she keeps it about 1/2 up. Well I was forced get behind the wheel to move it, so I jacked it down as low as it would go. This moved it a lot more back than I thought it would. BUT... that's not all. Once it was lower, pulling the handle actually allowed to move it rearward even more! It seems having it to full height limited how much the slide position could move back. Never experienced that before. And now that it's okay, I'm not planning to try to replicate the situation again.