Can't update apps from Apple Configurator 2 (apps are already up to date)

Solution 1:

I had this problem recently in macOS 10.15 (Catalina) with an iPhone 11 Pro Max.

The App Store app on the iPhone showed 19 updates available via a red badge on the app icon as well as inside of the app. Meanwhile, the Apple Configurator app on the Mac claimed no updates were available.

Restarting the iPhone didn't change anything as far as I could tell.

But after restarting the Mac and launching Apple Configurator again, it now showed 34 updates available, which still doesn't match what is shown on the iPhone, but I guess it's better than zero!

Clicking the Update button in Configurator resulted in the apps being downloaded and updated. By the time the update process finished, 32 updates were downloaded, and I received an "unknown error" on the last two.

Apple Configurator's handling of app updates seems to be quite buggy.