I configured my mouse wheel to scroll 12 lines each turn. This works fine everywhere, except in Edge (and any other UWP app).
I made a short GIF to demonstrate this. In the GIF you can see I set my mouse wheel scroll to 12 lines. Then I open up Firefox (left) and Edge Beta (right). I turn the mouse wheel down exactly once on Firefox and once on Edge Beta. Firefox correctly scrolls from line 1 to line 12. Edge Beta scrolls from line 1 to line 32!
@v-gapartYou haven't? I have yet to find a machine where I couldn't replicate this.
I reproduced this issue on my personal computer (Insider build 18990), VMs on my personal computer (1903), my work computer (1809) and test VMs on my work computer (various Versions). I got this issue since I joined the Edge insider.
It's not a scaling issue either. I don't use scaling. It also isn't a DPI issue, my scaling is always at 100%.
Have you tried reproducing this with the same mouse wheel settings that I used, between Firefox and Edge Beta? Or Internet Explorer (not Edge) and Edge Beta?