GimCat Hydro-Grass - cat supplements

I've been using this product for about 2 years. Everything was fine until a few months ago, when I noticed that not only does the grass not grow like it used to, but when I say it doesn't grow, I mean only a few blades come up, and they're really thin. I thought it was just a fluke, but the other 2 boxes I bought afterwards were the same. I hope the complaints are taken seriously and that the manufacturer goes back to the original formula.