The first time I run a simulation it takes half a minute or so to run. But when I modify the weights of the ranking system and run it again, it takes only a second to complete and there are no changes to the results.
It looks like ranks are being cached and not getting recalculated when the ranking system changes.
Please make sure that you click the Save icon after you update the weights. When you see “Weights Updated” message it’s not actually saving. To commit the changes you have to press the Save icon (the old style floppy disk) and you should get a “Saved!” message.
Let me know if that fixes the issue. If not we need to see a way to reproduce the problem.