Netflix loses connectivity to TV

I have a Control4 system that loses connectivity to my TV frequently and C4 are unable and unwilling to fix it.  I think it's a Roku thing, so I hope someone can help here

I use: 
* Samsung Q70 T
* Marantz NR1711 receive
* Roku Ultra (4660, 4661, 4662 series) 4660X running 12.5.5
* C4 system and C4 remote

When I select "Satellite TV" on the remote, I can access DirecTV fine. When I select Roku on the remote, I can get to the menu and most streaming apps fine. However, if I select Netflix from the Roku menu or Netflix from the C4 remote this always happens: I get the Netflix screen, select the user and then a few seconds later, I get a "no signal" screen on the TV (no audio, no video). If I wait ~5 minutes, it all comes back to normal. Sometimes this conenctivity loss happens an hour or so into watching Netflix as well. I ran a test on the HDMI cable that connects the receiver to the TV (I used the TV's testing app) and it's fine, so the problem is not the TV or the cable. When this problem first happened I bought a new Roku and the problem persisted. So the problem is the receiver or the signal fom the Roku. Please help!