I'm not sure exactly what you have set up. If you want to have a 5.1 system, then you run everything thru your avr. (I know nothing about how roku, Apple TV, etc. work, so, not talking about those devices). I also do not have earc in my system.
So, run your DVD/blue ray player, your direct TV and/or dish receiver all thru the avr (via hdmi). From your avr, you run a single hdmi cable (or, I assume earc) straight to your tv and it's arc/or earc connection. This will let you play your audio from these devices (DVD, direct TV) to your 5.1 speakers, as well as the video will show up on the TV. (You only need one arc out from the avr to the one arc input at the tv.)
The arc (earc?) is to run sound from your tv back thru the avr and out to your 5.1 speakers. You can also control the tv volume to the speakers with your tv remote this way.
My setup for years was (still is 5.1). Dvd, and direct TV went into the avr, then out to TV with hdmi. Earlier this year I did away with direct TV and now only stream from my smart(?) TV. So, to get 5.1 out my speakers when streaming TV, I had to redo my hdmi cable from my avr to the TV. I now use both arc connections instead of the regular hdmi connections. But, I don't know about earc. I only assume it's somehow similar without the physical connections?