I have written weeks ago, when Cubase 10 was released, about the “new” behaviour in the Key Editor, described here: Dropbox - File Deleted
Why haven’t Steinberg reacted?
Where - or to who do I turn to get attention on this??
I posted it on issues 15th of November!
Now obviously real life works that way - not everything that is wrong can be fixed immediately… 
I was hoping for a fix, now I just want to hear if anybody listened.
So do you have an answer, or just waisting your time?
I suppose a germane question would be whether you reported it via your Steinberg account.
I wrote about this issue the 15th of November in the General section, believing that Steinberg was monitoring the discussions here.
Well apparently they don’t or at least they haven’t responded to this subject. Maybe we are not that many customers on Mac with a 4k monitor??
The business/client relation here is pretty awkward. But maybe it’s a result of the mixed clients profiles, from amateurs and to us, that spend the entire work day with Cubase and Dorico. My expectations to Steinberg is equal to the expectations to the guy that tunes my Steinway, and the shops where I buy my hardware - Thomann -, is that wrong?
I have followed your advise and posted a ticket in my Steinberg account - after the obligatory question if I have looked elsewhere to find an answer - but I don’t have high hopes.
But I think it’s weird that an update like Cubase 10, that focuses so much on the GUI - with a lot of bells and whistles - can miss checking up on this.
Their support is on the level that they try to help you if you have a crash. But in general they try to get their users on to the forum where they can help each other. And I guess they use the buzz on the forum too. On some cases their help was to point out a forum thread that concluded that it does not work. I guess that they dont even have a clue internaly, or that code is so poor that they cant fix it.