After hitting a note background disappears

[vapayt]

I don't know if it is issue with browser (Firefox) or with game, here's a video:

Sequence.1.mp4

[HamnT]

Can confirm it's browser specific, issue doesn't happen in edge (and presumably any other chromium browser). It also seems to affect lanes lighting up on button press, firefox will only light up one lane at a time for me while edge can do multiple.

[Beelijah]

this also happened to me, using firefox as well.