1. You need to create an override file. Run the following command:
sudo gedit /usr/share/glib-2.0/schemas/my-settings.gschema.override
You can use your own name for the file "my-settings.gschema.override" but you have to keep .gschema.override part.
2. Put following code into the new gschema.override file
[org.gnome.desktop.app-folders]
folder-children=['']
3. Save that file, exit it and run following command to compile GSettings schemas to make your modification active
sudo glib-compile-schemas /usr/share/glib-2.0/schemas/
This schema will be activated during next system reboot so your settings will be kept. This modification will be applied for all existing users that are on the system.
4. Run dconf-editor application (if not installed, install it via Gnome Software or command line)
- navigate to:
org / gnome / desktop / app-folders and click on folder-children value.
A new window will pop up. Set the value "Use default value" ON (the default value should be [''] ). Custom value ['Utilities', 'Sundry'] should be gray now. Click on "Apply" button.
5. Look in Activities - there should be no group of apps anymore
6. Reboot your system and check if the groups are still off in Activities
