Well, for one thing, the token for a named clipboard is not the name of the clipboard in percent symbols, the way you are writing it. Check this page to see how you should be writing it:
The %NamedClipboard% token returns the text of a specified named clipboard. It has the form %NamedClipboard%% where specifies which past clipboard to use.
I don't see anything else wrong besides that, but I have to go get lunch now, so try taking this advice and see if it works.
Well then change it! You can change the font, the size, etc. inside that KM action. E.g., Just select the text you want in a larger font, and press CMD-= a few times. That will increase the font size. That's what I normally do. Or try right clicking inside the text field of the Insert action and look at all your options in the Font menu. You can even change text colour.
I suspect that the size difference is explained by your settings in System Settings, Displays, Larger Text. But if you like your custom settings, then you have to fix it using the method I described above.