Sounds like the same thing that happened to me, 2nd time I broke a belt too. First time, it didnt stall but I lost power like a transmission slipping and could smell the burning belt, pulled over got a ride home and loaded it into my truck.
2nd time it stalled out and wouldnt start just like yours, got it home and the belt had shredded and part of it got caught up in the variator /pulleys and tightened up so the engine couldnt run.
Got me a new Mollassi belt and now I check it real good every few thousand miles. Now that I`ve had it apart and back together a few times, its easy to do, quick, and prevents me getting ruining the scooter, getting into a wreck, or just plain being stranded again.
An ounce of prevention is worth a pound of cure