Yes, Cubase and Nuendo are old ladies. 
And there it is always dangerous when something is changed in the code. Even for long-time employees it might not be easy to always keep track of all dependencies.
But if it works for new functions, it should work even better for visual things. However, since many bugs in the GUI have been there for years, such problems really don’t seem to have a high priority at Steinberg. (Which I find unfortunate, since these things make fluent workflow unnecessarily difficult.)
I have published a similar problem HERE. Most users will hardly take notice of such trivialities. And Steinberg probably won’t either. But maybe they will surprise us. 