Can't Update FCPX

Hi folks.

My laptop version of FCPX and my desktop have gotten out of sync. For some reason the install on my laptop will not auto-update, nor show any available updates. When I go to my purchases in the app store, I see I can download an even OLDER version of FCPX, but it doesnt show the current version as even being purchased, even though my desktop shows it. When I hit download on that version it asks, "do you want to download an earlier version?" and of course no, so its aware of the existence of FCPX on the laptop, but it appears nowhere on my purchases or update options.

Any advice on whats going on? I'm on High Sierra on both machines, and in theory its all the same apple ID and the same logins, so I'm flummoxed.

thanks for any ideas.