Actually in some restaurants, not set Allow different guest groups to sit at the same table but there are still two orders on the same table.
Cause: Staff 1 creates order. Because of slow synchronization, such order is not displayed on the other staff’s device. At the same time, staff 2 creates order on the same table. Consequently, when device of Staff 1 is successfully synchronized 
there are 2 orders on the same table.
Solution: Delete one of 2 orders.
Note: When you see notification on outstanding synchronization, you should Synchronize manually (by clicking Synchronize icon on the device).
