Autoupdate not works


in WPMU DEV Dashboard > Manage I turn on "Enable automatic updates of the WPMU DEV Dashboard plugin", in mu-plugins.php I have add_filter( 'auto_update_plugin', '__return_true' ); but still I have to click to update WPMU DEV Dashboard and other WPMU DEV plugins.

Plugins by other authors autoupdates silently well without need of user action.

How to do it with WPMU DEV plugins too?

Thanks, Jiri