Does anyone know if cornstarch looses it 'potency' or ? Is there a time limit on keeping it stored?

I have some that I had transferred into a mason jar and vacuum sealed with my f.s. so wonder how long it can keep ‘doing what it is made for’ such as ‘thickening’ for different recipes, in other words the ‘shelf life’.

I am not sure at the moment how long ago I originally put it in the jar, but I reseal it when I use it. This is one of those things you don’t use that often I believe. If anyone has good suggestions on ways to use it up quickly please feel free to let me know, thanks