Steps to reproduce: 1) Enable Persian or Arabic keyboard layout to better see the problem. 2) Type two characters. They stick together. 3) Type one character, press space, type another. They won't stick but there is a space between. 4) Type one character, press shift+space, nothing happens. Type another character, they stick together. 5) Go to System Settings> Input Devices> Keyboard> Advanced> Unfold "Using space key to input non-breakable space character", select Non-breakable space character at second level. 6) Repeat step 4. Characters again stick together as the "non-breakable space character" is not working. 7) Try this on libreoffice, chrome and other gtk applications, the key combination works. What is wrong: The "non-breakable space character" settings cannot be enabled and the shift+space key combination does not work. What is expected: Shift+Space should type an invisible space character which separates two characters in special layouts like Persian and Arabic which stick together otherwise. Other information: Gtk applications work out of the box without need to change settings. Left Alt, Left Ctrl, Meta key, Right Shift, Right Alt, Right Ctrl, all tried and non works. Log out and reboot also didn't help.