Sport position is the more damping position. You have two adjustments, preload and damping. When you set the preload the damping will change also, on my R1200 GS I can also change the damping independently to fine tune the ride and as far as I know you can also. If running one up with luggage for example you can select sport for more rebound damping but it affects both ends.
On a recent tour on a R1200 RS the rear seemed low and I was grounding out in corners and the rebound too fast so I set it to two "helmets" even though I was solo with luggage and increased the damping to dynamic and it made a big difference.
Try changing preload to the next highest setting and then play with the damping and see if that cleans it up for you or set damping to the next level. The dynamic esa should react differently depending on settings. There should also be ride height calibration in the gs911 settings check if they are zero when the wheels are off the ground when in real time values.
