After upgrading to Veeam Backup and Replication 9.5 Update 4, you may start receiving failed protection group rescan reports saying:
No new hosts found.
[Error] Failed to process 1 host processed
This behavior is related to the introduction of an option to automatically assign licenses to all incoming standalone agents.
Currently this behavior is by design and may be changed in future releases.
As a workaround, you may go to Inventory node, right-click the Manually Added group and select Disable.