Anytime a snapshot device is copied and pasted into another program, the values will be "null". That is because there are no values of this device in the Global Default Preset, so they are now "null". (I know, I know, you just clicked on "Save Default Settings", but the cells were really null when you did the save, even though there were values shown).
The workaround would be;
In Edit Mode, select the cells and go to Device Properties. Turn on the "Control Accepts User Input".
Now after emulation and/or deploy, and in Gesture Mode, highlight the working controls and do a Copy. Now go to the "empty" cells, and highlight--paste.
That said, I've seen this before, but just "worked" around it. Now we're going to add to the Feature Request list that Snapshot values should copy/paste, as well as being able to define as a Plug-in.
Thanks for bringing it to our attention,
Make it intuitive, never leave them guessing.