Pressing character '0' toggles mute on/off.

Omeleto wrote:

Whenever i type '0' my volume gets muted on/off. Its acting the same as my F10 button. How can I disable it? Please help!

See >System Preferences>Keyboard> both Text and Short Cuts

and return to default.

Change Keyboard preferences on Mac - Apple Support

If no insight or resolve—

Uninstall any and all third party Antivirus, Cleaners, Optimizers, VPN, speeder uppers....

To trouble shoot further you can:

—Try a SafeBoot https://support.apple.com/en-us/HT201262

This test will tell you if third party interference; extensions etc are not loaded in safe boot mode.

—Test issue in another user (or guest user) account https://support.apple.com/guide/mac-help/set-up-other-users-on-your-mac-mtusr001/mac This will tell you if it a universal issue or isolated to your user/admin account. 

If this happens in Safe Mode even when you carefully make sure to only press 0 and not the adjacent key, then this would suggest a hardware issue with the keyboard itself. If possible, try with a different keyboard to see if the issue occurs or not.

Don't take this the wrong way, but... is it possible that this is "fat fingers" problem?

I often activate Siri when pressing delete, just because the Siri button in my touchpad is very close to the delete key...

Assuming that this is not the case: does it happen in a different user account? Does it happen in your account if you start your mac in Safe Mode?

Omeleto wrote:

Hi @leroydouglas,

Have already tried all the solutions you mentioned with an Apple Advisor earlier on. Didn't seem to work. Any idea?

So you are saying no change with a safe boot or new user account to compare.. (?)

You do not paint a very big picture—old issue, new issue , what changed...

Then to sort anomalies reinstall th mac OS and test before you move your user data back in.

How to erase your Intel-based Mac - https://support.apple.com/en-us/HT208496

How to reinstall macOS from macOS Recovery - https://support.apple.com/en-us/HT204904