Sounds like your monitor settings are not automatically being detected. Remember that linux is case sensitive.
Code:
sudo systemctl edit getty@tty1
Then enter this text and save the file afterwards:
Code: Select all
[Service]
ExecStart=
ExecStart=/sbin/agetty --autologin Your_username --noclear %I $TERM
To undo just remove the lines by running the systemctl edit getty@tty1 command again.
You should be solving the garbled problem versus finding a workaround.