I recently switched to using the Synology 218+ NAS and I'm now unable to pick see the Discovery Channel. I was able to do so running the TVE software on my Mac.
It's worth noting that when I was running the TVE software from my Mac, I was also able to pick up 120 channels (I'm grandfathered in with one of the original Directv Now plans). But with the NAS, I'm only picking up about 108.