I've recreated my issue with a simplified CodePen.   Without ScrollSmoother active, the middle (non-sticky) column scrolls perfectly as you'd expect while the other two columns remain in place.   Once ScrollSmoother is active, the height of the section is borked and no sticky scrolling occurs. What can I do to enjoy ScrollSmoother whilst still using sticky here and there as needed? (I've commented out the ScrollSmoother code in the CodePen - it's there to play with)