I'm with Uncle Bob - if you would give us a recipe we could probably help you more than just trying to "guess" blindly.
I, personally, can't think of any reason for your soup to get "gummy" from freezing using flour for a thickener. Using something like Xanthane or Gaur gum or ClearJel could be a problem - depending on the recipe, although I don't see how they could gum up your soup if used properly.
And, as mcnerd noted - creamed soups do not freeze well - they "break" when reheated, they don't get "gummy".
"It ain't what you don't know that gets you in trouble. It's what you know for sure that just ain't so." - Mark Twain