Some Windows Client's checking in but not updating DEFs.

In this particular location I'm running 12.1.2015.  All clients get their updates from SEPM.

I have a quite a few clients (about 25%) that "Check in" with the console normally (have a green dot), yet don't grab the updated DAT files.  I've tried pushing updated content and even reinstalling the client from the console using a new package.  Yet, they stay with the same Definition version.

Anyone else have this issue?

We have 4 other locations on the same version and aren't experiencing any of these issues!

The Windows Event logs are clean.

Please help!