In case of multiple notifications from the same site (pushed by Chrome browser) Notification applet in tray shows only last one.
E.g. using this demo https://gauntface.github.io/simple-push-demo/ I pushed 3 notifications, but in tray I see only the last one.
At the same time system notifications pushed by notify-send tool:
showed as expected, every notification is in the list.
Is there a way to prevent notification overriding?