RBR50 message on ROKU says" HDCP unauthorized content disabled

I don't think this has anything to do with the network, it is more likely a problem between your ROKU and your TV (and whatever HDMI cable you use to connect them). 

Try these suggestions:

https://support.roku.com/article/208755468-why-do-i-see-a-purple-screen-or-an-hdcp-unauthorized-message-when-i-try-to-play-content-

Hope this helps.