This is what happens to some users of Nike's iPhone app and has been trying to update for a few days but to no avail. In all cases versions where it was "locked" 6.3.1 and when you update an app to appear, it's already turned.
It may be that your app is a good update but that is not the case in all cases though it is true that Nike Run Club works well. The update was released on December 16
This is an improvement added to this released version:
A new postcarrera experience. This new version comes with updated interface, embedded metrics, powerful map views and improved rhythm tables to see your work.
There are users who have worked on auto-renewal and already have version 6.3.1 and others who have manual updates and do not renew more than they try. In some cases a IPhone has restarted or deleted the app directly to reinstall it
It is clearly not a major problem as in most cases, but it does. Not the first time the same thing happened and that at this time there are many things that do not allow the update of this version of the app. Are you aware of any cases?