"Update" no longer showing in Testflight?

Hi,


Recently when testing we've seen that having an older version of an app then trying to update to the latest version via TestFlight no longer seems to show, it only shows as "Install".
Previously we've been able to test older (or app store versions) of the app, then update via TestFlight and it updates the build like it would on the App Store, however pressing install seems to delete it and replace.


Has this changed recently or is an issue for anyone else?


Thanks