Enabling removable media automount settings only takes effect after re-login

To reproduce: In removable media settings make sure "mount removable media when inserted" is off. Turn it on by ticking it. Insert a removable medium such as a DVD. It will show up on the desktop (provided the desktop has been configured to display its icon), but it will not automatically mount. Only after you log out and log in again will the change in settings take effect. In contrast, turning off that option immediately takes effect.

(xfce 4.20.1 on Manjaro)