this thing happens to me all the time. normally i refresh the page, it happens again, i refresh the page and it's fine on the 3rd time. still really annoying
it happens when you load a track and it says "CLICK TO RESUME". When you click then press f the glitch happens. You have to refresh the page until the track loads without saying the click to resume message, then pressing f is normal
but with polygons mod, there is a option to never have CLICK TO RESUME, I haven't had the problem since I started using his mod
A way to know ahead of time whether or not you will get the glitch: If it says click to resume after refreshing, you will most likely have the glitch and you will be forced to refresh your page once more. I plan on fixing this in Free Rider Lite (assuming I haven't already unintentionally)