Second project Migrate button is greyed out

Question

I am trying to migrate an unowned project into an organization. I have all the necessary access in the target org as I just successfully migrated another. I have verified that I have the various rights as well as owner on the unowned project. In the Migrate project "projectname" spawned window after I click the Migrate button across the top of the page, it defaults to the desired organization and won't allow me to select anything different (I thought the other toggled between No Organization and the desired target org). The project ID for this unowned project begins with the desired target organization name and I wonder if that is causing the issue? Project id is essentially"targetorgname:descriptor". Any assistance would be appreciated. If there is a bug here, what is the path to migration given project IDs are not editable?