I came across this issue on a couple of SharePoint farms.
When i was trying to patch a SharePoint 2013 farm i ran in to a problem that the SharePoint Config Wizard told me that it needed updates on some servers within the farm. The strange thing about the updates was that they were installed.
So how can we make sure that we can run the wizard and properly update the farm?
After searching a little bit on the internet i came across the following blogpost on TechNet. The blogpost mentioned as a solution to run psconfig –cmd upgrade –inplace b2b –force –cmd installcheck –noinstallcheck and start the sptimer service when reaching step 4 of 5.
These steps made it possible for the psconfig to complete successfully.
However it turned out that this was not the correct solution. It made the farm somewhat unstable, the farm reported still that updates were missing.
Open a PowerShell window as administrator and run Get-SPProduct -local on the server which is missing the updates according to the SharePoint Wizard.
This turned out to be a much more elegant solution.
These problems seems to be related when the SharePoint servers receive the March 2015 Cumulative Updates via Windows Updates.