I get the same message. Today it said 3 apps needed updating. All apps in the Hub were up to date. I opened each Samsung app. Link and S Health prompted for updates. When I clicked on update, it takes me into the Samsung Hub. Interestingly, there is not option to show updates in the Hub. Yes, one can go through the settings to find the three apps listed there. When I select Purchased, there are no apps listed (I've not bought any through Samsung, nor would I when I have Google which is goes across all Android devices).
For the other apps, there is no check for update option in the settings. To me , it is a poor design to have a notification that goes nowhere when selected. In this day and age, one should not have to hunt for updates by going app by app. I still don't know what the third app is to be update.d