I have just seen, that the scrolling is slow even with the key command.
The main culprit here seems to be the variaudio tab in the inspector.
But: usually once the tab is opened, it stays open for all events (at least in my projects), so if you use variaudio after that, you don’t have this issue.
Yes, that can be a workaround, but I don’t use VariAudio, I just want to bugs to get fixed 
Edit : Oops seems like there’s no workaround except from resizing the window !
Oops, yes, you’re right, if i open the sample editor with the VariAudio tab open, it scrolls quickly. If I close and reopen the tab, or if I have to switch to the tab because another tab is active when opening the editor, it is slow.
Extremely stupid. I will open a support case, too, and another one for the left zone/definition tab bug, although I don’t expect to hear back from support until in a few weeks…
Yeah usually they take about 2-3 weeks to answer. I also informed them again about the bug in my open issue report. But if you take a look how fast the ticket number rises, its no surprise. I have no problem waiting as it is not a major issue preventing me to work, as long as it gets fixed in the next maintenance updates.
I still think Steinberg could really benefit from a public beta and a proper bug tracking system for beta users… This closed communication system is a thing of the past imho.
Absolutely agree.
Still present with 12.0.40 although the release notes state the following :
“Vertical scrolling speed in VariAudio editor now works consistently.”
It’s been two times in a row, the 12.0.30 release notes told the same thing and it is still not fixed.
Come on !
Hmm… that’s a shame; its scrolling consistently fine for me now , nice and speedy, without having to do any re-sizing or touching nothing…
Are you sure ? You need to close the Editor tab and open it again.
Actually the closing/opening of the VariAudio tab doen’t trigger the issue anymore but it comes back when closing and opening the Editor. So the issue is still not fixed.
Yes - just been doing that loads of times; lower zone, or pop out window.! Selecting and de-selecting data; closing the editor window, re-opening etc, etc… With 12.0.30 I would easily have seen the old slow behavior by now…
Sorry but it’s still present with the Lower Zone Editor.
They took two updates trying to fix this and it still isn’t fixed entirely. WTF.
Sorry, perfect for me now.!! Lets see if others join in… 
[EDIT - no its not; see below.!]
OH.! MY.! GOODNESS.!
Ok, so if I do as you do in your GIF (switch to another Tab and back to Editor Tab in Lower Zone) then I get the slowdown…!!
Oh dear…
Still, whatever they’ve done, I’m happier with it currently, than I was in 12.0.30 
Still not fixed in 12.0.50.