Recently, the App Store told me that there are some upgrade available, but non of the upgrade can be completed, just keep on spinning. OS 10.14.6, App Store 3.0

Thanks so much. Yes, it is weird. 😅 When I force-quit the appstoreagent in Activity Monitor, the apps in App Store spinning stop and resume to the original upgrade button. Then I upgrade the apps again and they go fine. 👍☺️

A similar issue happened in another Mac (MacBook Pro 2018 OS 11.2.1) also today. An upgrade of an App in App Store stop and hold still at about 80%, doesn’t like the other Mac that kept spinning.

So I force-quit the appstoreagent in Activity Monitor, then the App store turns back to upgrade available again and the upgrade works the whole way through.