OpenRA

Hi, was wondering if anyone knows how to overcome this annoying issue that happens when i click download button beside a played match on RAGL result page when using Google chrome. When I then click on game replay it waits a few seconds then opens a new Firefox window. Where it then asks me to save file. Once I click save there. If I go to download folder, i have downloaded file twice.
So currently I just shut Firefox window when it loads then wait, then pick next replay then shut Firefox and repeat. It didn't use to be like that for me. But just don't know how to stop it doing it? Has anyone else experienced this? Or is able to suggest how to stop it happening.