Clippings lose their selection highlight when you click somewhere outside the clipping after selecting text. But the text is really still selected, and you can affect it by clicking on a dropdown to change the font name or font size. This is bizarre because you can't see the highlight on the selection, so you won't know what text will be affected.
Steps to repro:
Create a clipping.
Select some text in the clipping.
Click somewhere in the whitespace around the box surrounding the text or outside the clipping altogether in the clipping panel (but not in another resource).
Click on the font name or font size dropdown to select a different font or size.
Result: A ghost selection still exists where you had selected the text, even though the highlight is gone, and the font changes on that text.
Expect: The font dropdowns should be disabled (the way all the other ribbon tools are) when the clipping doesn't have the focus.