Next time you retract the slide watch the topper fabric as it rolls on the drum. Ours makes a light thumping sound each revolution of the fabric. The fabric isn't perfectly aligned with the drum and I can see the drum move on the mount as it trys to compensate. When it warms up a bit I'll reposition the drum to square it to the fabric and hopefully eliminate the thump.
When the fabric is fully rolled on the drum check both ends. If the drum is off center the fabric will appear to be rolling uphill on one end
2013 Adventurer 32H