Mouse-wheel scrolling numbers on the trade site

I used to be able to click on the number entries and scroll the values up and down with the mouse-wheel. After not playing for a few months, I came back and it didn't work anymore.

Is that something in firefox settings or am I missing something on the trade site? I thought it was in firefox, but for the life of me I can't figure it out.

omg thanks for posting this. I had this exact same issue and this fixed it. I wonder why firefox randomly decided to change this value