[ubuntu_mate] Streaming media over powerline

I have a raspberry Pi B+, coected to an 8-bay HDD enclosure. I recently bought and ODROID C2, with the intention of setting it up on another TV, and stream my movies and TV shows to it from the Pi.

Everything is set up and coected, but when I try to play anything, it opens in VLC, the timer bar moves, but I get no picture. If I pick out a random time, it will display 1 frame, like a screenshot, but nothing more, and the timer keeps moving.

The setup as it is now goes: Pi, directly coected to the 8 bay enclosure->Powerline adapter->Router->Powerline adapter at the router->Powerline adapter at the ODROID. The drives are 2x4TB seagate ST4000DM000.
I've tried removing the Powerline at the router, to see if it made a difference, but nothing changed.

Is it too many steps to be able to playback? Are the drives too slow? Is it a USB limitation?
Any help would be appreciated