lighdm runs wrong command

Config:
# cat /usr/share/xsessions/kodi.desktop
[Desktop Entry]
Name=kodi
Comment=This session will start Kodi media center
Exec=kodi-standalone
TryExec=kodi-standalone
Type=Application
# cat /etc/lightdm/lightdm.conf.d/50-myconfig.conf
[Seat:*]
autologin-user=kodi
user-session=kodi

This results in the following log output:
[+0.40s] DEBUG: Session pid=1673: Started with service 'lightdm-autologin', username 'kodi'
[+0.42s] DEBUG: Session pid=1673: Authentication complete with return value 0: Success
[+0.42s] DEBUG: Seat seat0: Session authenticated, running command
[+0.42s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+0.42s] DEBUG: Session pid=1673: Running command /usr/sbin/lightdm-session /usr/bin/openbox-session

I.e. a completely different command from what is specified in the configuration is run.

However, if I create a new user `xbmc` and change the config accordingly, to `autologin-user=xbmc`, I get the following log output:
[+0.43s] DEBUG: Session pid=1678: Started with service 'lightdm-autologin', username 'xbmc'
[+0.46s] DEBUG: Session pid=1678: Authentication complete with return value 0: Success
[+0.46s] DEBUG: Seat seat0: Session authenticated, running command
[+0.46s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+0.46s] DEBUG: Session pid=1678: Running command /usr/sbin/lightdm-session kodi-standalone

I.e. with a new user, the correct command is executed.

So is there some hidden user-specific config file somewhere that I have missed, or is there something else I can do to salvage my old user, which currently boots into an unusable state?