I don’t know how you have “downloaded and staged the install” …
However, I can tell you that BatchPatch can apply feature updates in two different ways, either by using the built-in Windows Update actions (make sure the update classification ‘Upgrades’ is checked under ‘Tools > Settings > Windows Update), or by using a deployment with the ISO media:
https://batchpatch.com/deploying-windows-10-feature-update-version-2004-the-may-2020-update-to-numerous-remote-computers-simultaneously