Hey,It means the PC doesn't detect any device. Make sure the drivers for your device are installed.
The "default" at the end of the command is supposed to disable it permanently, and it works fine for me.
On my Poco F3 (installed in fastboot) it doesn't work, it disables these icons only temporarily.
I noticed that after rebooting it still works, but that it was only after a few hours that it doesn't work anymore.
Are the 'adb' commands to be executed on a switched-on smartphone?