Apple - Mac App Store shows update count but section is collapsed/empty

Had the same problem. Solved by going to the "Purchased" tab on the App Store, looking for software that needed to be updated (xCode, iMovie, GarageBand, Numbers, Pages, Keynote) and clicking there on "Update". I also started downloading a new App. Some 15 secs later they appeared on the "Updates" tab as well. Including a "Software Update" that contains a new iTunes, what I was looking for actually.

Same issue here. Count 6...

Tried:

MAC:~ sudo softwareupdate --list
Password:
Software Update Tool
Copyright 2002-2015 Apple Inc.

Finding available software
Software Update found the following new or updated software:
   * iTunesXPatch-12.5.2
    iTunes (12.5.2), 145964K [recommended]

MAC:~ $ sudo softwareupdate --install --all
Software Update Tool
Copyright 2002-2015 Apple Inc.

Finding available software

Downloaded iTunes
Installing iTunes
Done with iTunes
Done.

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After this, down to 5, but still wrong..

The App Store was showing a badge count of 4 items to be updated on my Mac (macOS 10.12.1) but nothing was displayed in the 'Update' tab.

I suspected that Pages, Numbers & Keynote apps probably had updates waiting given that their iOS versions were updated earlier today, so I located those apps on the 'Featured' page of the App Store and saw that they had an 'update' button. So I updated all three from there.

After that, I went back to the 'Update' page of the App Store and found that iTunes 12.5.2 updated was now displayed and could be updated.

Badge count is now zero!