Is there another way to adjust the radio's volume other than the scroll wheel, such as a dev command?

For some reason my scroll wheel won't move the slider up or down when it appears (Gmod's weapon HUD and physgun scroll seem to work fine).
I've tried adjusting the mouse settings between in-game and computer settings, verified cache, etc.

Out of curiosity, I even tried it on my laptop since it's a different operating system, same issue.

Other than that, the addon works perfectly, though the music is too loud.