Scrolling Through File List and Slide List Using Mouse Wheel (Mac)

[GordW]

Still learning PTE AV Studio, but liking what I can do with it so far. I have it installed on a Windows machine as well as a Mac and notice a difference when using the mouse wheel to scroll. A furth enhancement is that I have and use a Logitech MX Master 4 which has a horizontal scroll wheel by my thumb. (Works great with Lightroom Classic).
Sorry for this long explanation of my experience, but here goes....

Mac...
When the cursor is within the file list, I can scroll with two fingers; moving up and down. Scrolling left or right does nothing. When the cursor is within the slide list, similarly, I can scroll left and right through the slide list and scrolling up and down does nothing. It depends on where the cursor is whether I scroll up/down or left/right. That is how I expect it to work, and it does.
When I try scrolling using either the vertical or horizontal scroll wheels on the mouse it depends on what the last action was, as well as where the cursor is located. If I use the trackpad first to scroll up/down through the file list, then then vertical scroll wheel scrolls through the file list, as long as the cursor is within that area. The horizontal scroll wheel does not scroll through the slide list even if the cursor is within the slide list area. I first need to use the trackpad, with the cursor within the slide list, then the horizontal scroll wheel will scroll, as long as the cursor is within the slide list. Once I scroll through the slide list, I then need to use the trackpad to scroll through the file list before I can use the vertical scroll wheel on the mouse to scroll.
I was expecting the scrolling on my mouse to work the same as the trackpad; depending on where the cursor is located scrolling vertically through the file list, or horizontally through the slide list. I have my MacBook connected to an external monitor and it's a bit of a hassle to have to reach to the trackpad to be able to then use the mouse to scroll through the particular list (files or slides).

Windows...
I can scroll using the vertical mouse wheel through both the file list and the slide list. It depends on where the cursor is (either on the file list or the slide list.). The horizontal mouse wheel does not do anything. I'm not sure if it is supposed to. I'm not too worried about the Windows experience as my main driver is the Mac. But, I wanted to see what differences there are between the two versions.

Thanks for reading through this lengthy and convoluted attempt at explaining my situation. Am I missing something in my Mac setup? Or, is that the way it is supposed to operate? Any suggestions would be appreciated.