App store have to tap update twice
I've been having this issue for quite a while on my iPhone now. The system is up to date.
Every time I click update, after the download & installation is finished. The update button appears again.
It looks like it is not picking up the latest update—the first update only updates the app to the version before it, only after tapping the update again the app is up to date.
iPhone 12, iOS 15