The core problem is that xfce4settings daemon, whilst spawned by ubiquity-dm it end up defunct. it should be running properly and thus displaying background during ubiquity-dm session. this is a regression in the xfce4settings or it's looking for something that is missing in the environment.
The core problem is that xfce4settings daemon, whilst spawned by ubiquity-dm it end up defunct. it should be running properly and thus displaying background during ubiquity-dm session. this is a regression in the xfce4settings or it's looking for something that is missing in the environment.