Belts can squeal.....glazed clutch pads can cause jerks, slips, judders.
My scooters require a brisk takeoff to get clutch 'hooked-up' quickly which prevents glazed clutch pads.
Very gentle takeoffs lead to poor drivetrain behavior on all my scooters.
Most do not like poking along at low speeds.....need motorcycle gears for that.
I would return to dealer and have them test drive since you are still under two yr warranty.
Sorry it doesn't perform as good as your other scooter.
Stig