I’d go thru the options both in Cubase and your soundcards just to see if any changes might be affecting performance. Any of you overclocked? That can have a bearing.
Also, although my system was new when C8 came out, those with non-SSD drives might need a thorough defragging after the installation which is largish. I have noticed since C8 installation, while not much of the above issues, that my C drive has been using more space than is usual. Could be Cubase, I’m still looking at it.
Might be time to transfer some of these issues to the Issues section.
nb: Fragmentation can affect some programs in very strange ways as they look for their bits and pieces all over the drive. The program slows down and functions can get sluggish or even fail. The more you use Cubase the more it has to look for. Things will overtake each other, cancel each other out as functions are overtaken. When this happens things can look like bugs. Then there are real bugs…
Now we need a real expert to tell me what really happens. I’m just guessing from my own advice from my tech friends. Some of which advice works, some doesn’t. Hope some of this works for you guys.