What grade of paper do you finish with?
As crazy as this sounds the blade may be too smooth for the sheet to stick to it.
I used 60 for initial and 150 for final. Actually, the other way round, I guess the rougher it is, the less the scuff tends to stick to (based on my observation that after the rough 60 grit sanding, scuff sheets didnt stick earlier at all and any sheet will stick well on something like plastic which is theoretically equivalent to very fine sanding). Maybe I need to go finer than 150? What is the final sanding size you guys recommend?