virtualbox.org

It took me months of googling and trying to find this:

• Download Nvidia Inspector
• Start nvidiaProfileInspector.exe
• Create a new profile and name it VirtualBox
• Add virtualbox.exe as application to the new profile
  Change: Since VirtualBox 6.0 you have to add virtualboxvm.exe
• Scroll down the list and change the following two entries in the "Other" section:
  1. Buffer-flipping mode: 0x00000001 OGL_FORCE_BLIT_ON
  2. OpenGL default swap interval: 0xF0000000 OGL_DEFAULT_SWAP_INTERVAL_FORCE_OFF
• Apply changes

This eliminates the flickering for me in VirtualBox fullscreen mode with 3D acceleration enabled

That's a really interesting solution Mirji, thanks for posting it! And thanks for updating the ticket as well! Kudos!

Just updated to VirtualBox 6.0.6, extension pack and virtual machine drivers, with VBoxSVGA the problem is solved