Morphous and Inconsistent RPMs

HI all
So I have Helix, pull the throttle, strong consistent pull, steady fast and predictable rpms from start to finnish, solid RPM rip all the way through

The Morphous upon throttle pull, moves to about 5k rpms, then kind of goes down to 4k, then 4.5k,,,,then hold at 4.5k rpms even though WOT,,,,then at about 45 mph, RPMs increase linearly and solid all the way up to max

IS this a design flaw with yamahas CVT or just some issue with the OEM rollers not being optomized for the morphs low end, I hear many people complain about the morphs sluggy low and mid performance

I am doing an OEM belt change and going with the Dr pully 13g hoping it will iron out this issue, I hear good things about these sliders and should do just that

Anyone have an idea why the Morphs CVT does this?

TY all
Peace