Powerpoint Slide Wont update for user

We have a link to a PowerPoint slide inside a document library. when most users access the link they get the latest and greatest PowerPoint. However, i have a user which is in the home owners group that does not get any updated versions. When they open the PowerPoint, they get it in edit mode, they click "enable edit" and they are told that there is a newer version on the server, would they like to download it? we click yes, and the PowerPoint refreshes, however, it is still the old one. The cache is refreshed in the browser, so the person should be receiving the latest file. the versions inside PowerPoint match the versions on the server, but we are just not getting it for this person... Is this a power point issue or a SharePoint issue? What gives? This is for SharePoint 2013 on premisis