Keebmonkey WK870 Barebones Mechanical Keyboard

My dude, I had the same issue as you, including only audiowave working, and finally found the answer. Fn + L toggles the light... It's that goddamn easy. That function apparently supersedes everything from the app except audio wave, I guess because it's an app-only function. That fn shortcut guide was in the shitty pamphlet you got with the board but for some godforsaken reason available anywhere online. I had to pause on an unboxing and zoom in to find the guide. https://youtu.be/n2G0eIjhr70?si=aRuWBbq7ilBfFN-a&t=179 That's pretty unacceptable IMO, but I guess that's just what happens when you roll the dice on a budget keyboard.