Hello, I have a ScrollBox setup for my UI, and in-engine it scrolls perfectly fine, however once packaged for HTML5, the scroll speed is VERY slow in the web browser, and the scroll-to-zoom feature i have for zooming the springArm camera is also significantly slower, I was able to multiply the scroll amount to work around that issue, but the scrollBox is still slow.
I see that this issue was reported before here UMG ScrollBox scrolls very slowly - UI - Unreal Engine Forums
and that this was “fixed” Unreal Engine Issues and Bug Tracker (UE-34811)
but appears to still be happening in HTML5. Using the scroll bar works normally.