mousewheel up and down events were initially not working on my bumblebee status bar. After verifying on the command line, it seems that wpctl set-volume command requires sink ID first and percentage change as the second arg.
steps to verify, assuming wireplumber is installed and sink ID is 32
```sh
wpctl set-volume 32 50%
```
will set the volume to 50%
```sh
wpctl set-volume 50% 32
```
will result in `Object '52' not found
