When you enter Full Screen mode, the target's full screen is displayed and acquires the same resolution as the target server.
The hot key used for exiting this mode is specified in the Options dialog, see Tool Options.
While in Full Screen mode, moving your mouse to the top of the screen displays the Full Screen mode menu bar. The behavior of the menu in full screen mode is affected by some options on the Tool Options menu. See Tool Options > General Settings > Full Screen options
If you want the menu bar to remain visible while in Full Screen mode, enable the Pin Menu Toolbar option from the Tool Options dialog. See Tool Options.
If you want to access the target in full screen mode at all times, you can make Full Screen mode the default.
Note: Not available in LX2.