how to press CTRL+SUPER+D/CTRL+ALT+0 on Ubuntu guest

[vb_user_6128]

I am running a Ubuntu 20.04.3 LTS guest on a Windows 10 host. When I lauch xfreerdp from within the Ubuntu guest, it opens in full screen mode, hiding my Ubuntu taskbar and top bar. The only way to view the taskbar and top bar from this point is to minimize the xfreerdp window using a keyboard shortcut. In my version of Ubuntu, CTRL+SUPER+D minimizes all windows and CTRL+ALT+0 minimizes the active window. My problem is that I cannot seem to get this key combination to register in the guest OS - it's instead being picked up by the computer I am connected to via the xfreerdp window (a Windows 10 machine). How do I send CTRL+SUPER+D and/or CTRL+ALT+0 to the guest OS? I've tried pressing right CTRL (i.e. the host key) and I've also tried using the on-screen keyboard (Input->Keyboard->Soft Keyboard from the VirtualBox menu) but neither work.

[scottgus1]

If the special keyboard shortcuts work in the Ubuntu VM OS when xfreerdp is not running, but they fail and get sent to the remote computer when xfreerdp is running, then this problem needs to be solved in xfreerdp or in Ubuntu. Note that Virtualbox needs to send these keys into Ubuntu to get the Ubuntu OS to respond to them, so Virtualbox cannot introduce any key blocking, or the commands would stay in the host. And Virtualbox does not have any key-blocking capabilities aside from the host-key combinations used to control Virtualbox.

A remote software's job is to pass control signals to the remote PC. If xfreerdp has a keyboard-shortcut-blocking feature, block those shortcuts in that feature.

Else, solve the original problem:

When I lauch xfreerdp from within the Ubuntu guest, it opens in full screen mode, hiding my Ubuntu taskbar and top bar.

Get it to not open full-screen, but in a window.

So far this is not a Virtualbox problem.