We recently migrated from 3.6 to 4.0, but I'm a little confused about how to keep the nodes up to date. I see the auto-updates come through for my 4.0.3 nodes, but they don't seem to upgrade them to the newer 4.0.x releases.

Is there a way to do this upgrade?  I have two nodes that were installed with 4.0.3, and I would like to bring them up to the same version as everything else.  

For reference, the 4.0.3 nodes were built off the 4.0-2016083011 iso, and the 4.0.6 nodes were built off the 4.0-2017011712 iso. 

Thanks, 
Thomas