A console shortcut can be intercepted by the Linux host even while a virtual-machine window is visible. Repeatedly pressing different combinations can leave you looking at the wrong login screen. Establish which operating system should receive the keys before using a console for troubleshooting.

Write down the guest's name and the exact reason for opening its console. Save work in both environments where possible. Check the guest distribution's documented console and graphical-session shortcuts, including the route back, before leaving its desktop.

Use the guest-specific control

GNOME documents a keyboard button in the running box's header bar for sending key sequences directly to that guest. Open it and select the intended combination from the available list. Its documented options include several Ctrl+Alt+function-key combinations.

GNOME gives Ctrl+Alt+F3 and Ctrl+Alt+F1 as console/desktop examples for some Linux distributions. These are examples rather than a universal mapping. Use the target guest's instructions, and avoid selecting unfamiliar combinations whose effect you have not established in that system.

Observe the result before typing credentials. Confirm that the login prompt belongs to the guest, using its known identity and the surrounding Boxes window. If the entire host desktop changed instead, recover the host view using its own documented route before trying again.

Keep the diagnostic action narrow

Once in the intended guest console, perform only the planned check. For example, record the displayed error or determine whether the guest responds independently of its graphical application. A usable console does not by itself explain why the desktop stopped responding.

Return through the guest's documented graphical-session sequence and confirm that the same guest application remains visible. Do not cycle through unrelated key combinations hoping to find the previous screen.

If no expected console appears, keep the exact sequence and observed display in the support note. Distinguishing host interception, guest response and the route back is more useful than reporting that the keyboard does not work. It also prevents a guest troubleshooting attempt from disrupting an unrelated host session.

Sources: GNOME documentation.