Hello Tom DS,
Thanks for your message.
You are getting this error message because the account is signing in to that company's tenant.
If it is a Microsoft account To solve this, open an incognito tab and try signing in freshly into your microsoft account using https://account.microsoft.com/account/manage-my-account
For error reference, See: "Your account has been locked. Contact your support person to unlock it, then try again." error when signing in to Microsoft 365
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola