4k not working through AV receiver
I recently purchased a new 4k UHD TV and received the XG1v4 after contacting comcast support. I use an Anthem MRX 720 receiver for all my AV connections. The receiver just passes the video signals through. The receiver is connected to the TV via a high-speed HDMI cable. The XG1v4 is connected to one of the HDMI inputs on the receiver.
In the Device Settings->Video Display section of the X1 settings, there is a message that 4K UHD is undetected.
When I select either of the 4K output resolutions anyway, I get a black screen which eventually goes away and the original 1080p resolution is still in place.
An Apple TV connected the same way (using the same cables and ports) is providing full Dolby Vision 4K UHD so I am confident this isn’t an issue with the receiver or TV or cabling.
There seems to be a problem with the ability of the XG1v4 to properly detect 4K capability.
Is there a firmware update or something that I might be missing on the XG1?
Please don’t suggest that I connect the XG1 directly to the TV. That works, but not supporting an AV receiver is unacceptable.