Erase shortcut won't work

What I want is for the top button on my pen to be my eraser shortcut

But instead, it pulls up the color selector that appears when you right-click, which I really don't even use.

I use Wacom Tablet Properties to edit all my shortcuts, and it's still set to erase but it's not working properly

I might be overlooking something, but changing keyboard shortcuts isn't working and the button on my pen is activated right-click as well but I don't know how or to get it to stop.