Before you start, close VirtualBox! After those manipulations start VB as Administrator!
Screen Resolutions
: 1280x720, 1920x1080, 2048x1080, 2560x1440, 3840x2160, 1280x800, 1280x1024, 1440x900, 1600x900
Description:
macOS_Catalina - insert your VB machine name.
1920x1080 - put here your Screen Resolution.
Cheers!