While the Group Post Notifications appear as the red dot mark on the bell icon of the Android Mobile app's Home, the Offline Invites do not behave that way. You can see the invites if you manually see them by clicking the bell icon.

Also, while the Group Post Notification pops up as an OS-level notification while the phone is in standby mode, the Offline Invite doesn't.

Overall, the Offline Invites don't work as notifications, significantly decreasing its usefulness.

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