Updates not updating?

My iPad Air 2 says there are 5 updates.

However, when I go to the updates tab in the App Store app, these five apps are listed as they would be before updating, but immediately, they show the 'Open' button instead of the 'Update' one, as if they had already updated.

I have tried restarting the iPad and verified that the iOS is up to date.

My iPhone6s+ is updating correctly with the same level of iOS.

Have you force closed all open apps? Press the Home button twice, then swipe up all open apps? If you have already done this, did you force restart your iPad Air 2? Hold both the On/Off button and the Home button for 10 - 15 seconds until the Apple logo appears. Then let it restart.

I tried deleting one of the Apps and then reinstalling it. As it was downloading it still showed up as if it would still need to be updated.
However, once it finished downloading it showed as updated today, with the other four also now allowing me to update them.

Very strange