MTP is a lousy, unreliable, clunky protocol for file transfers. It sucks on Windows, and it sucks even more on Linux. Sometimes it will work fine, other times the phase of the Moon is wrong, and it won't work at all.
I use ES File Explorer, and just copy any files I want to transfer onto a Samba share. That said, I think I'm running an old version as it started asking for permissions I didn't want to give it.