I recently installed Ubuntu 18.04 (previously 16.04) and an important feature is missing: the option to switch between GUI and TTY.
From the GUI I can switch to one of 5 TTY, by Ctrl-Alt-F2 to Ctrl-Alt-F6. I can login in the tty, do whatever I wish. When I Press Alt-F1, I get to the login-screen, not back to running GUI session. Alt-F7 leads to a black screen.
When I switch to the login screen, and login, I get a fresh GUI-Login. The programs have been terminated, the unsaved data and status is lost. This is annoying.
In previous versions, Alt-F7 brought me to the original, running GUI. Alt-F1 brought me to the console of the GUI. This is how I want it to be. The particular order of screens does not matter - the crucial item is to get back.
How can I customize 18.04 in this way?
PS: I basically have the default 18.04.4 desktop install using GNOME-shell (not unity). The only thing remotely non-standard is that it is MBR/Legacy, not GPT/UEFI install.