When installing a new license to Backup & Replication, it does not apply. Specifically, after running a job or after a period of time, the new license appears to revert to the previous license.
This occurs when Backup Enterprise Manager (BEM) is in the environment and is still distributing licensing for the given Veeam install with the old license.
To resolve, either update the license installed in BEM, or detach the relevant Veeam install from that BEM instance.