im on a mac and had the same issue.
other bugs: when i pan around (while zoomed far in), the planes arent in a fixed position on the map, they shift with the pan
ux bug: when i zoom in, it zooms into the middle of the browser window instead of where my cursor is.
I will take a look to fix these bugs.
also fixed the parallelex problem of route trail vs. the plane icon
I just modified zooming algo a lit, now it should improve your user experience.