I'm showing the attached when I log on to my iMac. When I go to the app store and click on updates it shows as one is available but then not there. Hopefully the screen shots will explain better!
Tried this but no joy. When I log onto my account I don't see an option for Hide or Unhide purchases. Anymore suggestions? Again I enclose a screenshot from the support page, and how it looks on my Mac, greyed out with no options.