Hi John,
You can invite the guest users not create a new user, are you sure it is not invite and you have created accounts?
Invite a guest user
Authorization
Authorization to invite guests is controlled by your directory settings. The value of these settings can be seen under "Settings" on the "Organizational relationships" page.
Authentication methods
Guest users authenticate to their home Azure AD tenant. If the user forgets their password, the guest user or an administrator in their Azure AD can reset it. Your Azure AD authenticates the user by a federated sign in with the guest user's Azure AD.
Email
To be invited as a guest, the person must have an existing email account, and their email address must end in a domain name that is not a verified domain name in your Azure AD. Azure AD will send the guest user an email with a link that the user must click in order to begin collaborating.
If you need to create or invite a new user and you are not in a role authorized for that, you will need to get help from an Azure AD administrator. An Azure AD administrator can create the user for you, or assign you to a role in Azure AD that enables you to do so.
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