It is unknown to me what those recipient addresses are for, which is why it's hard to bang my drum about about if either the shapeshift failed or the coinbase transfer failed in some way. I assume there's no way of investigating this further?

I didn't in this instance copy and paste the bitcoin address, I used the shapeshift inbuilt feature in Jaxx and then a scan of the qr code for coinbase. Testing this however it did not change when I copied and pasted