Please follow the steps below:
 

1. Enter the APP homepage, the device page displays all the created groups, long press the corresponding group;
 

2. In the pop-up menu, select "Group Information" to enter the group settings page;
 

3. Click "Group management", then click the symbol "-" on the right side of the corresponding device name to remove, and then click "Save";
 

4. Turn to the main page of the APP，try to click the group switch button to test whether the removed device has been removed; if it has not been removed, please remove it again.