Enabling push notifications in Firefox for websites (such as gmail) does give notifications on my desktop (ubuntu). However, any notification seems to disappear very quickly, usually 2 sec but maybe up to a minute depending on if I move my mouse over the notification or if I refresh the notification tray. I would like to have these notifications stay displayed in my desktop notification until I intentionally dismiss them. My desktop settings for notifications from Firefox are the same as those for applications which do have notifications which last until I dismiss them. I am guessing it is setting in Firefox that I need to change. Is this setting something I can change?