Make sure that the accounts used to grant consent in the ODM tool are Global Admins for source and target Tenants. After the consents have been granted, GA role can be downgraded.
Make sure that the accounts that are used to grant consent, are the same as the accounts configured under Migrations > Accounts > Configure Connections
Go into ODM, click on Migration > SharePoint > Configure Project and make the fields for 'Source SharePoint Admin Center Url' and "Target SharePoint Admin Center Url " are filled in with URLs that can login to the source and target Sharepoint Admin centers, respectively.
Run a Refresh Project task on the SharePoint project's Dashboard page.
Then run Sharepoint Site discovery again. And then re-migrate the Sharepoint site.
