Loading while shared streaming?

I would be guessing that the TV is not connected to the router but a PC. That means it could be over WiFi and since WiFi is Half Duplex, you can incur a lot of delays.
http://www.makeuseof.com/tag/what-is-half-duplex-and-full-duplex-operation-and-how-does-it-affect-your-router/

Loads due to slow network speed....I assume your TV is connected via wifi.

connect TV to router using cable.

When you are experiencing buffering or constantly loading this usually indicates that the television is not getting sufficient speed to play the video. You can make a wired connection from the television to the router to get more speed. Other ways you can help the speed get to the television using a wireless connection, would be to change the channel the routers on. Sometimes your signal can get interfered from other devices in your home. By changing the channel this will put the signal on a different wave so to speak. You can also try moving the router closer to the television, or get a wifi booster to keep in the room with the television as well.

I hope this helps!

Regards,

HD Tech