There's nothing an app can do to effect if/when the status bar icon of a notification is shown since the system handles that, so this must be a system change.
Unless Android has changed, the status bar icon should be shown every time a new notification, with a new id, is posted.
Maybe you've changed your flow so it's now executing the Notification show block in a new fiber each time, that would give it a new id every time causing the icon to appear.
Try rebooting the device to see if there's any change in behavior.