macOS Monterey 12.6.9 unable to update.

Usually when this command is used " sudo softwareupdate -i -a -R "

This is to get around the Loss of Administrative Privileges on the Admin Account of this computer.

In which case, I am not 100% sure the " softwareupdate --fetch-full-installer --full-installer-version 12.6.9 " is going to allow the Actual Installation process to commence.

Once the" Install Monterey " application is launched, it will required the Password of Admin Account of this computer.

Should it work, great

If not and am driving another link regarding the Difference between an Owner Account and a Admin Account

It is specific to Apple Silicon Computers

The " Owner Account of this computer "  has that privilege to add, remove, upgrade or downgrade accounts. This would include adding more Admin Accounts and / or downgrading an ADDED Admin account 

Set up users, guests, and groups on Mac

Normally the " Owner Account  " is the very first Account used when the Computer was Very First Setup as New and out of the box.

Below link will provide additional insights about the Difference between Admin Accounts and Owner Accounts  

https://eclecticlight.co/2021/07/18/last-week-on-my-mac-the-perils-of-m1-ownership/

If in doubt about admin from your logged in user account,  from Terminal.app copy and paste —

dscacheutil -q group -a name admin

Credit for above belongs to @leroydouglas

What is the output of the above command

The I suggest running this command below from Terminal.

If it works, it will Only download the Full Version of Monterey 12.6.9

It will not Auto Launch

It will place the " Install Monterey in the Applications folder 9 about 12.xx GB in size

Be sure the computer has at least 50 GB of Empty space to allow the 12.xx GB application to download, then Expand and only then it will commerce the installation process

When ready, launch the Application like any other and follow the prompts

Arank02 wrote:

it's demo, and it's listed.

Okay, then what you see is normal. "root" is in every ones Mac but is not listed.

FWIW, the command P.P. left out was probably…

softwareupdate --fetch-full-installer --full-installer-version 12.6.9

I'm going to assume your admin name is not demo.

Is "demo" listed in System Preferences > Users & Groups?

Sorry and lucky another user picked up on missed Terminal command

softwareupdate --fetch-full-installer --full-installer-version 12.6.9