I think the problem here is that the asset is already in a frame of its own. You're trying to place the content of that frame into a different frame.
I fear you might have run into a hard place with a rock.
Rather than copying and pasting, perhaps you can interrogate the placed image to get the link address then use that to place the original image into the frame. Although, having done that, you might then need to make other adjustments to the newly placed image (such as scaling/offsetting/skewing/rotating, etc.).
These will be images that the customer does not actually send in. We send out proofs and this graphic will replace the improperly packaged image(s) and act as a place-holder. We find irrefutable evidence that customers do not understand that just because they see it, it doesn't mean that it is there. Their response is "It's on the page". For the last few years operators would make the frame "non-printing" in attributes. The problem is that those same operators would forget to uncheck the option once the pic was obtained. Viola! Blank spot in book, our fault...money, money, money.
We would like to have a script to the dirty work and eliminate some of the human error.
The cutting and pasting of the placed library is actually placing a frame in a frame also. I would have to select the frame contents (direct select tool) to illeviate that, then delete the asset's placed frame.