Rice wine making stucked half way, fermentation never happened?

I am trying to make glutonous rice wine, purchased the so call yeast from asian market, the white cookie/powder broke rice down into sugar.

I have measured, it is 40%, very sweet to taste. But it just does not ferment. The sweetness always there, does not reduce.

I tried to pitch the champage yeast into it, it only last 2 days, before bubbles stopped. Why?

Is it too sweet (40%) for champage yeast?

Thanks