There was a bug in a previous version of 10.12.x App Store where the most recent updates would not show up under "Last 30 Days". I experienced it at the time, but since a few updates ago, the problem seems to have disappeared for me.
Try restarting, open the App Store and see if the list corrects itself.
On a Mac since 1984.
Currently: 24" M1 iMac, M2 Pro Mac mini with 27" BenQ monitor, M2 Macbook Air, MacOS 14.x; iPhones, iPods (yes, still) and iPads.
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