Hovering mouse wheel over a speaker icon brings volume down, but not up
Basically as the title says. Hovering a pointer and using the mouse wheel over a speaker icon (without clicking) to reduce or increase volume in Linux DE's is a normal thing.
Parole allows only decrease, while increase doesn't work. It's not entirely unresponsive, but not usable.
For example, from 100% to 0% you can go in just a few wheel scrolls. However, from 0% it only goes up to about 2% then it refuses to increase.
This message is displayed in terminal every time you try to raise volume with a wheel:
(parole:26678): xfconf-WARNING **: 01:48:17.242: Failed to set property "parole::/audio/volume": Operation was cancelled
Arch Linux, Xfce4, latest official versions.