Personally I'd save for one of these-- Sony VPL-VW295ES-- native 4k, superior color and brightness - everything cheaper is really just a 1080p projector with upscaling.
If you are experiencing this and are not using a vpn, have properly assigned a static ip to that computer and forwarded your port, then I'm sorry to tell you in my opinion it's the router itself.
I used to use the N7000 and it also had an issue with Plex remote steaming. I switched to an Asus...
The Alamo is indeed available on television in hd somewhere. The theatrical cut is floating around the internet, done kind of foreign airing with Spanish credits, but English dialogue.