Morph - new rollers + belts, bike won't go over 30mph / 5k rpm

I have a morph with 6k on it. Decided to swap out the rollers and belt with some new ones, as I don't believe they had ever been changed in the past. Simple enough task, I've done it a few times on other scooters.

I bought an OEM belt, couldn't find rollers in the 25x15 14g size so I went with sliders instead. I went about installing them, took it for a test ride and it wouldn't rev past 5k rpm and barely hits 30 mph. Thought I might have done something wrong, so I went back and reinstalled the old rollers with new belt. Same thing. Then I reinstalled the old rollers with the old belt. Same issue.

I'm at a loss as to why this could be happening. I've been torqueing the variator down to around 60-65 ft lbs and the clutch nut to 40-45 ft lbs. If anyone has any suggestions as to what could be the issue, please let me know.