After upgrading to 18.04 my screen suddendly switched upside down, since my Laptop apparently has a rotation sensor. I temporarily fixed it with xrandr -o normal and disabled the gnome rotation sensor, because I could not fix the problem by physically holding my laptop upside down.
The problem is, that the rotation switches back to inverted with every restart.
I tried to write a script, which executes the xrandr command with every restart and added a xrandr --output eDP-1 --rotate normal in the gdm3 file, but none of that works.
Is there any way to set the default orientation back to normal or write a working script, which fixes the problem at a restart (including stand-by).