@VenessaG #scrollbar - I don't know if this would work for you, but I've never used the horizontal scrollbar.
I have a MacBook Air and I use the right/left buttons that look like arrows to the right of the Option key.
In fact, I didn't realize there was a scroll bar until you mentioned it. 😂
Sometimes I use two fingers on the track pad.
The only scroll bars I use are the vertical ones, but usually I use the trackpad and drag things around, both up and down.
@J_Windrow I'm on a Windows machine and the arrow keys don't move the layout. But someone suggested holding shift while using the mouse scroll wheel and that works :)