Lock Home screen layout in Mobile Phone
Android new version have the option of Locking the Home Screen layout. If you are experiencing issues adding, removing or moving applications on your homepage you may have enabled this feature.
1. Toggle on/off Lock Home screen layout
2. Once you have enabled Lock Home screen layout, you will be unable to relocate or remove any applications on the home screen means if you try to move drag anything from home screen it will stay as is.
This also means, if you have enabled this setting you will not be able to add applications from your apps tray to your home screen.