Poor video quality when streaming from NAS or Internet

I have the WD TV Live used for a while with a USB harddisk and USB stick directly connected to the device without any problems. I’ve always had poor video with streaming services like Youtube but always thought it was a problem with the Youtube app on the WD. However, I have now connected (wired) the WD via the LAN to a Synology DS212j and have the same problems. I use a Sitecom 300n router but with a Netgear router I have the same problem.

The first seconds are okay, but then you see a lot of compression artifacts. After a while this repeats, so good quality. 

Is this a known problem and if so, any tips to improve the video quality. 

What firmware do you have?

. You should not have any problems like this if the drive is wired to the router

Possibly a duplex mismatch? I can’t remember if the WDTV lets you set this manually or not, but make sure that both are set to Auto for Ethernet or if manual that both are set to same speed and duplex.