Unable to turn off VoiceOver with Command + F5 keys

Re: Voiceover will not turn off with Command and F5 KEYS

You may want to check if there are settings in place for that on your Mac

Apple Support's online article (link below) says:

"Use a keyboard shortcut

You can use a keyboard shortcut to open the Accessibility Shortcuts panel, where you can turn accessibility features on or off.

1. Press Option-Command-F5.
2. Or, if your Mac or Magic Keyboard has Touch ID, quickly press Touch ID three times.
3. In the panel, select the features you want to turn on or off, then click Done. Or, click anywhere outside the panel to close it.

Additional accessibility shortcuts you can use and customise can be found in Keyboard settings.

On your Mac, choose Apple menu  > System Settings, then click Keyboard

in the sidebar. (You may need to scroll down.)

Click Keyboard Shortcuts on the right,

then in the dialogue that appears, click Accessibility in the sidebar. See Use macOS keyboard shortcuts."

Above info. comes from:

Quickly turn accessibility features on or off on Mac - Apple Support which also has other suggestions and tips.