Unfortunately, syncing to Ipods has been broken for a long time. Apparently Apple started encrypting some portion of the ipod which makes it hard/impossible to sync using anything other than Apple provided programs (like itunes and Apple Music).
Apparently anything as new as a 4th gen ipod nano has this encryption. So your 5th gen touch is almost certainly one of the modern ones that can no longer sync with MC.
I was messing around for a while with doing a handheld sync to a directory on my hard disk. Then using itunes to move those files to the iphone where I played them with a third party app. But it was too awkward and I mostly gave up on it. My iphone has no music on it at the moment.
Good luck to you.
Brian.