I have had two Sony X900H 65" TVs have the same issue (random green flash across screen). I replaced the first one because Best Buy said they had never heard of this problem with this TV, but the replacement TV is having the same issue. I have four devices plugged into the HDMI inputs. HDMI 1 - Comcast box; HDMI 2 - XBOXOne; HDMI 3 (ARC) - Sonos Beam ; HDMI 4 - 4K Fire Stick. I am experiencing this green flash across HDMI ports 1, 2, and 4, and also using an antenna. It happens randomly, sometimes once per day, and sometimes a few times a minute. I have tried unplugging the HDMI 1 and 2 devices, and it still occurs when using the HDMI 4 port. The common denominator is that the Sonos Beam is always connected. I have a higher quality HDMI cable I am using to connect to the HDMI 3 ARC port. I am wondering if anyone has experienced this, and if there are settings I need to adjust that is causing this issue. I had read some online about HDCP handshaking issues, but I'm not sure what settings I need to adjust to see if that is the problem.