To get stuff displayed in the control tab of the PaperUI, you must have Items defined and linked to the channels of the things.
By default, PaperUI has “Simple Mode” activated for Item Linking (PaperUI → Configuration → System)
With this mode on, when you click on the channel radio button (within the configuration of a Thing), you get the Items auto-created and auto-linked to the respective channel. Most likely, you already did this step (check the radio buttons under the Thing channels in PaperUI… expand them and see if there any linked items listed there)
Since you already have auto-created (and auto-linked) Items, yes… you should have values for each item… you don’t?
Correct.
In my breakfast, I defined my Items manually (using a /etc/openhab2/items/ZWave.items file)
I recommend the same (switch off Simple Mode, use the Channel names as they appear in your PaperUI and create an *.items file)