In my UltraEdit Professional Text/HEX Editor (x64) version 22.20.0.49 on Windows 10 64 bit it is no longer possible to scroll in the browser view pane.
It was possible in previous versions, and I wish it will possible again soon.
If I open on Windows 7 SP1 x64 in 32-bit UE v22.20.0.49 a *.html file, use Window - Duplicate Window, and use on the duplicate window View - Toggle Browser View, it is not possible to scroll in browser view.
But if I disable browser view on duplicate window (file name on file tab ends with :2) and enable it instead on initial window of the *.html file (file name on file tab ends with :1), scrolling in browser view works.
Please report this issue by email to IDM support as this is a user-to-user forum, see top of the page.
Best regards from an UC/UE/UES for Windows user from Austria