iOS - old versions of app getting installed from the App Store

Question

We just had an app update get approved in the App Store today. However, on some devices, when we download the app, even after completely deleting it first, it is installing the

Answer 1

Have these devices ever installed your app via TestFlight? We had this issue and TestFlight was causing a similar issue. We would try to download the app from the App Store, and an older app version would be installed. Funny enough, after installing this older app and returning to the App Store, we would be informed that there was an update available for our app, and we would be able to update to the correct version at this point.

Removing TestFlight and its associated profiles didn't seem to help; a factory reset of the phone did the trick.