I had a server which was showing up in the PM console with its correct product version but was showing as having its signatures way out of date!
When I checked the actual server, this wasn't the case as the FS GUI showed it was up to date and so did the logs - no connections problems.
Therefore, I assumed this was a PM status anomaly and removed the host from the PM console and I've been waiting for it to be rediscovered since.
I'm still waiting for it to appear several days later. Is there a reason why the PM doesn't see it? Normally, my PM even sees hosts on the network which don't have any AV on them!
I've even polled the PM from the server by initiating a manual update and a policy update and the logs clearly show the connection with the PM is successful too.