are you sure don't have conflicting configurations, one system wide (/etc/xdg/rncbc.org/QjackCtl.conf) and another user local (~/.config/rncbc.org/QjackCtl.conf) ?
are you sure you have the correct configuration as last you've run qjackctl? are you switching different users or even machines ?
that is totally weird! o.O
are you sure don't have conflicting configurations, one system wide (/etc/xdg/rncbc.org/QjackCtl.conf) and another user local (~/.config/rncbc.org/QjackCtl.conf) ?
are you sure you have the correct configuration as last you've run qjackctl? are you switching different users or even machines ?
byee