Why might an app not appear in the Google play store?

A team previously published a DAB app which is available from the play store. Recently the app was rebuilt and published to the play store, but the new version is not seen for installation. I am asking on behalf of a team and I don’t know the exact details of how it was published to the play store the second time.

What factors might stop the new version of the app being available for download / installation?

Thanks

Does it show in Google that it has completed review? It might still be in review.