Remember the calculator is simply calculating the odds of victory or loss based on casualties from weakest to strongest in attack or defense value. meaning it is removing the weakest units first followed by better ones later.
incorrect Triplea version…check to make sure you have the latest (1.25 i think).
that you haven’t dled the proper maps…make sure you’ve done this.
if it’s that you can’t host that’s the problem, you probably haven’t enabled port forwarding to host games.
They explain how to do all this in the link above.