A couple of possibilities.
If you 100% have fuel going through and you have a good strong, consistent spark then I would be doing a compression test at this point. Which is what your issue sounds like to me from experience (I wrench on scooters for a living and hear those lines "I was riding and suddenly lost power, now it wont start" every few days) Nine times out of ten, It's due to lack of compression.
But, It could also be that while trying to restart it, you have flooded the engine.. easy enough to sort, whip the spark plug out and crank it over a few times, pop spark plug back in and see if it fires up.
But again, Compression test it. The "poor mans thumb test" is just a no no. 10psi will blow your thumb off exactly the same as 90psi will. Get a tester and see what its at.