Com base na resposta this , fiz o seguinte e funciona.
sudo nano /etc/gdm/gdm.conf
Neste arquivo, adicionei a seguinte linha.
FirstVT=7
In
/etc/gdm/gdm.conf
you can set what the 1st terminal should be the graphical interface.FirstVT=7
will make GDM check tty7 first (by the way: this could mean it ends up on tty8, tty9 if these are enabled and tty7 is not free.If this is inactive in
/etc/gdm/gdm.conf
it will probably randomly start with tty1 and if that is active (ie. a terminal session is open) it will pick tty2 and so on.