- VirtualBox: 5.2.12 (just released)
- Host: Windows 10 with the latest update
- Guest: Ubuntu 18.04, 3D acceleration enabled, Gnome desktop manager
- Video card: Nvidia GEFORCE GTX980
Ubuntu boot, login go fine, desktop shows up, I'm able to start applications, type, move or resize windows (by grabbing the edges), etc.
However, if I maximize any window by double clicking on its title bar, or clicking on the maximize button, response to keyboard or mouse input for the entire system becomes so sluggish (20 seconds or longer response time to any key pressed in gedit for example) that Ubuntu becomes unusable and needs to be shut down (forcefully if I don't want to wait for delayed response to commands).
If I disable 3D acceleration in VirtualBox Manager, Gnome works fine, even when maximizing windows.
If I switch to Unity desktop manager, everything works fine, with or without 3D acceleration.
Since my current Ubuntu 18.04 installation is an update from an older version of Ubuntu (16.04 was the original installed version I think), I created a fresh Ubuntu 18.04 virtualbox, and the same thing happens there too, so it's likely unrelated to the updates.
Also, generally Unity seems to be faster than Gnome, even when Gnome is still responsive.
This issue started with Ubuntu 17.04 (when Gnome was made default desktop manager) and has been happening with all versions of VirtualBox versions available since then.
I would appreciate any suggestions on how to fix this.