Hey @Sandeep_Gupta,
Thanks for the thorough write-up. Our team was able to review a fresh set of Roon Server log which help paint a clear picture of what might be going on.
Your HDMI output shows up in Windows as a device called Intel(R) Display Audio, that’s the endpoint behind the zone you named “Anker HDMI.” Between roughly 2:10 and 3:30 PM on August 5th, Windows added and removed that device more than a dozen times. Each time it vanished, Roon had no choice but to drop the zone. That’s the “I can see HDMI listed intermittently” behavior you described, and from our side it looks like this:
{"status":"Lost","reason":{"reason":"device_not_available"}}
That message means the Windows audio device itself disappeared, not that Roon lost track of it.
Why you see bars moving but hear nothing
When the zone stayed up long enough to play, Roon was genuinely sending audio. We can see clock-synchronization data in the logs that only appears when audio is actively streaming to a live device. So those meters are real, Roon is handing audio to the HDMI port. It’s being lost somewhere between the Anker dongle and the Anthem actually rendering it.
This is also why duplicating your display didn’t help. It isn’t that HDMI is “looking for video”, the link itself is unstable. A monitor is a much simpler handshake than an AV receiver: an AVR negotiates EDID, HDCP, and a separate audio block, and marginal USB-C adapters very often pass video perfectly while failing on the audio side. Your monitor test doesn’t clear the dongle.
Two things worth flagging
The zone you’d previously set up as “HDMI USB Anthem” wasn’t carrying HDMI audio at all, it was bound to a C-Media USB sound card chip, not the HDMI path. Only “Anker HDMI” was ever the real HDMI output.
Second, the Anthem isn’t appearing as Roon Ready on your network. Across three days of logs, the receiver only ever announces itself over AirPlay and Chromecast, never over RAAT. The zones you’ve been using (“Anthem Chromcast” and “Living Room Air Play Anthem”) are those two. That fits with the firmware not pulling: until the receiver updates, a native Roon Ready zone won’t show up.
The upside is that those Chromecast and AirPlay zones streamed reliably right through the logs, including several uninterrupted hours yesterday. You do have a working path to the Anthem today.
What to try, in order
- Swap the Anker dongle. This is our strongest suspicion. The add/remove pattern we’re seeing is the classic signature of a marginal USB-C adapter. Try a powered USB-C to HDMI adapter, or a Surface dock with a native HDMI port, so the adapter isn’t relying on bus power.
- Turn off Exclusive Mode on that zone — Settings → Audio → the gear icon next to the zone → uncheck Exclusive Mode. We can see Roon repeatedly failing to grab the device in exclusive mode while it was mid-disconnect. This won’t stop the dropouts, but it’ll make the zone usable whenever it is present.
- Test the link outside Roon. Set Windows’ default sound output to the Anthem and play a YouTube clip. If Windows drops it too, that confirms this is happening below Roon entirely, and the fix is in the hardware chain.
- Update the Intel graphics driver on the Surface Book 2, but from Microsoft’s Surface driver pack rather than Intel’s generic installer, since Surface uses a Microsoft-signed variant. The Display Audio endpoint comes from that driver.
- On the Anthem, set the HDMI input you’re using to a fixed 2-channel PCM mode and turn off any auto input-switching or eARC negotiation on it. Then confirm the receiver is actually switched to that input while Roon shows “playing.”
- For the firmware, the Anthem updater generally needs the receiver on Ethernet with unrestricted outbound access. On an eero mesh, try connecting it to the primary eero and confirm client isolation isn’t enabled.
A few questions that would help
- Does the Anthem hold a stable picture from the Surface for hours, or does the video blink too?
- What’s the exact Anker model, and is it bus-powered or does it have its own power input?
- Which HDMI input number on the MRX 1140, and does that input have ARC/eARC enabled?
- Could you try the Surface’s HDMI output into a TV instead? That would tell us quickly whether it’s the dongle or the receiver.
Thank you!
