After upgrading from version x to a newer version. You might choose to upgrade your beacon or agent manually. Once this has been done, there is a chance, or you noticed that the agent or beacon downgrade from the most recent version to an older version.
There are multiple scenarios this might be happening:
Beacons are set to stay at that level through automatic deployment
Unable to select the most recent version to deploy
Within Discovery & inventory > Settings
Under Inventory Agent for Automatic Deployment
Beacons have two places that control what version they are running:
If you press the edit button next to the beacon in question
These drop downs are controlled by your adoption table within your database, if these are not showing the most recent version then this will be why your beacons and agents are downgrading. If this is the case, then move over to scenario 2.
This scenario follows on from scenario 1, when the options that you can select does not include the most recent update. The problem stems from the adoption table not having the most recent version stored within it. This usually is caused by either the config.ps1 not being ran or not completed fully.
To rectify this issue.
Re-run the config.ps1 and allow it complete. If you notice any errors check where it errored out.