Horizontal scroll using SHIFT + mouse scroll wheel not working
I'm having a small issue with horizontal scroll in Firefox. I'm using a MacBook Pro with an external mouse. On Macs, holding SHIFT while scrolling the mouse scroll wheel allows you to scroll horizontally, rather than the default vertical scroll with no keys being pressed. However, this is currently not working for me in Firefox. When I scroll the scroll wheel without pressing any keys, the vertical scroll functions normally without any problems; when I hold SHIFT while scrolling the scroll wheel, nothing happens at all. No horizontal scroll, nor vertical scroll.
I have tested this in Brave on this same system, and both vertical scrolling (scroll wheel) and horizontal scrolling (SHIFT + scroll wheel) are working correctly, so it would seem this is an issue with Firefox. Does anyone know how this issue can be fixed?
Thank you, David