After a fresh install of the stable version, python and a lot of stuff installed too and a few days later, while everything were good,
I did an “aptitude update” which strangly made my system only display on the laptop screen, I no longuer could use my two AODC screen through my dell dock.
My first thought was to open ~/.config/monitors.xml but it wasn’t there.
After digging a while, I finally found a fix on this blog:
pkill -9 -f gnome-settings-daemon
Once done, the monitors.xml file was reset, and my screens back.