I moved Steam folder to another partition that's not mounted at startup using a symlink: How can I move Steam's download folder?

Now after every login it thinks it's not yet installed. I checked the package files and there are no XDG autostart. Any suggestion how it even gets launched?
Nothing in /etc/xdg/autostart, ~/.config/autostart and in systemsettings.

Steam->Settings->Interface->Run Steam when my computer starts not checked.

P.S. I'm on KDE and I don't want to automount the partition.