Ubuntu 19.10 on VirtualBox - screen not refreshed

Please see the screen capture that I attached.

I'm running VirtualBox in Windows 10. Ubuntu was just installed and I already installed guest additions.
The screen turns like this no matter what display resolution or scaling is set.

Graphics controller is VMSVGA. 3D Accel turned on (but it was like this even when it's turned off).
I set Video Memory to 64 MB.

I'm sorry if this was asked and solved. If so, please direct me.

Thanks

Namui

Attached Images

• Untitled.jpg (164.1 KB)