I have just done a number of “package updates” (by clicking on the red button on the dashboard) the boxes are at different locations around the globe so have happened overnight and still to prompt on other boxes as they wake up.
They are all Ubuntu systems (different versions) all on Virtualmin 7.7
No obvious issue the packages were all installed without error 
However, on returning to the Dashboard it still shows them as outstanding.
Going through the process again still lists them to be added but requesting install goes through the installation (apt-update?) - only to show “nothing added”.
This is pretty obvious as a caching problem. So going direct to Software Package Updates -> Refresh Available Packages forces a clear cache and a refresh. This does resolve the problem.
My question is “Is there any reason why this doesn’t happen (cache clearing) at the end of the update?”