So I assume this is new behavoir since the clutch work ? Are you aware there is a measurement for the thickness of the clutch stack that must be correct ? This is the equivalent of a clutch adjustment on other bikes. The correct thickness of the stack of clutch plates is how you end up with the correct clearance between the clutch and pressure plate. A new set of plates is sometimes too thick or thin so if the pack isn’t the correct thickness you may have to swap in used plates of other thicknesses to end up with the correct pressure plate clearance. Without that, you have shifting problems.