Magic Keyboard shortcut keys

There is no match of your picture in my Keyboard System Preferences in the sub-windows labeled Keyboard, Text, Shortcuts, Input Sources, Dictions. Instead, there is this

Under System Preference > Keyboard > Shortcuts > Keyboard, the following keys did have checks.

F1, F2, F3, F4, F5, F6, F7, F8

As you directed I unchecked them. By doing so their font became subdued as shown here.

There was no results when the brightness keys were tested.

Under Mission Control the F11 & F12 were checked. I also unchecked them.

Testing volume control afterwards was a negative results. Oddly enough there is no listing for F9, the mute key.

And then there is this odd duck.

I say odd because the keyboard does not have such keys.

Eight hours later and by accident, I discovered that the up and down arrows control audio volume. However, I do desire to have the top row of keys to function as their symbols depict.

Also, my previous post about the up/down arrow keys controlling volume was only applicable on a You Tube channel. It did not work on a Facebook or HBO Max video.

Does this also apply to a Magic Keyboard without a Keypad?

Your previous post about compatibility is regrettable information.

Here's hoping that Tom Gewecke (see above) may be on to something.