Domain management tenant settings
Domain management tenant settings are configured in the tenant settings section of the Admin portal. For information about how to get to and use tenant settings, see About tenant settings.
Allow tenant and domain admins to override workspace assignments (preview)
This setting controls whether tenant and domain admins can override existing workspace domain assignments. When disabled, tenant and domain admins cannot reassign a workspace that is already assigned to a domain to another domain. When enabled, they can override such assignments. The setting is enabled by default. The domain REST APIs respect this setting.
To enable/disable the setting, go to Admin portal > Tenant settings > Domain management settings, expand Allow tenant and domain admins to override workspace assignments (preview) and set the toggle as desired.