I've linked Microsoft to-do with Samsung Reminder. But, the snoozes and new tasks added through PC To-do, aren't syncing with Mobile(Samsung Reminder). If I add task from PC Microsoft to-do, I've to open the To-do tab in Samsung Reminder, then only it gets refreshed Synced. And the reason why, I linked To-do with Samsung Reminder is, it gives loud alarm kind of Reminder notifications, but with this Syncing issues, it's same as the rest. Syncing is OK With PC, if I add task, snoozes through phone, It syncs always.
Please register your concern in Samsung Members Application (Open Samsung Members Application > Get help > Send Feedback > Error report/Ask questions).
