Have you check the folder of your beacon with the inventories ? (ProgramData\Flexera Software\Incoming\Inventories)
If there are many files and the number is not decreasing fast, it means your beacon take tome times to the FNMP (network issue, overload, ...).
Could try this :)
Are you running on HTTP or HTTPS? If HTTPS it is important to ensure the certificate was pushed to the UNIX machines correctly. The next troubleshooting would be to validate that the policy was downloaded for each agent. However, today that requires logging on to a machine which fro 40% of 25k is a lot.
These were non UNIX devices. Also I can see that the policy wasn't downloaded on machines we looked at, not sure how to get the policy to download at this point.