@chengyun.yang-
Thanks for providing the detailed explanation on how the gpu cards work with the two API systems. I'm glad to hear that my (very limited) understanding of the differences between the two was incorrect.
As far as the issues goes, it always happens after Fusion has been running. I don't believe that its ever happened at the start up of Fusion. It seems like it tends to happen when there are things going on that require some sort of large change in the display. It has happened when, for example, when I close the open data panel. The window resizes and, sometimes, everything goes grey. I've also had it happen when I have more than one document open and either switch between the windows or they are being opened or closed.
97% of my usage of Fusion is a work, where my HP 15" ZBook is connected to an Apple Cinema display via a Thunderbolt connection. This single Thundrerbolt connection also supplies a couple of USB connections and my Ethernet connection to the ZBook. My work setting is where I have the issue. The other 3% of Fusion usage is at home, using only the laptop display. I can't be absolutely sure, but I don't recall that I've had the issue when working from home, with just the laptop display. I might have to do some more testing to confirm this.
The ZBook has the Quadro 2100M video card, but also has integrated intel graphics. I've never specifically tried to disable the Quadro card and just run the integrated graphics. The card is running whenever I'm "plugged in", but switches to the intel when on battery. I haven't really used Fusion for very long, when running off the battery. I know I've never had the issue when running Fusion on the battery, but it's such a short amount of time and very limited in what I'm doing, that I don't think it provides any data in diagnosing the issue.