Locked out of my Mac air with mouse cursor stuck in left hand corner. Password not being accepted.

Hi Jerseyman,

Welcome to Apple Support Communities. We understand that you're having an issue with your MacBook Air. We'd like to help.

What were you doing with your Mac when this issue started? Was this the first time you were using it today or were you using it and it stopped responding? Have you restarted your Mac yet? If not, that can help! Log out, sleep, wake, restart, or shut down your Mac

If needed, follow the steps under Shut down by the "Important" label. This will direct you to force restart your Mac if it's unresponsive.

Let us know if that helps!

Cheers.

Jerseyman,

Thanks for updating how things are going.

Sounds like the store erased and resinstalled the macOS on the device: Erase and reinstall macOS

We're glad to hear that things are now working as expected.

Have a great day!