[ubuntu] seamless mode / dual monitor in virtual box not activated

I am new to Ubuntu, and originally, I installed Ubuntu 18.04 LTS as dual boot along Windows, allowing the Ubuntu installer to help me build the partitions. After several months of never using my Windows partition, I have decided to install Ubuntu natively, using Virtual Box's guest Windows 10 as a "just in case" I need to use Windows for work. I am now running 18.04.1 native host, and I would like to run Windows 10 guest full screen in virtual box. I have three monitors, and I am trying to make my display show all three monitors in seamless mode. I have installed Windows to my Virtual Hard drive, however, I can't get the seamless option activated in virtual box to show the display in full screen, and also when I run the Windows virtual machine, I don't get more than one monitor window. Here are my system specifications.

spects.jpg

I have activated the display option two show three monitors
settings.jpg

but when I open my machine, I only get one monitor windows, and the seamless option is not available
machine.jpg

Also, the option to enable the second or third monitor is not available.
display.jpg
Please help me! Thanks anyone.

Attached Images

• spects.jpg (105.8 KB)
• settings.jpg (56.9 KB)
• machine.jpg (54.8 KB)
• display.jpg (45.4 KB)