(answer of [this post][1] used as a basis)

Perhaps try the following;

    sudo tee -a /etc/init/tty3.override <<<"manual"

If there are other TTYs with such issue, change the 3 to the TTYs number or just follow the solution I've linked above 


  [1]: https://askubuntu.com/questions/357039/how-do-i-disable-virtual-consoles-tty1-6