HDR / Dolby Vision no longer working on Xbox Series X

After one of the recent console updates (within the last 2-3months), I've noticed that HDR is no longer working for any game on my Xbox Series X. All required check boxes under the 'Video Modes' sub-menu are present and I previously had all green ticks (and no errors) in the '4K TV Details' sub-menu. I have not made any setting changes to my Xbox or TV, and my gaming hardware setup/equipment has also remained exactly the same. I have written below in great detail as I simply want to avoid being asked to repeat unecessary troubleshooting, provide Tech Support with as much helpful information as possible and provide other customers experiencing similar with a well-documented issue log.

Troubleshooting completed so far:

- Three photos of my various Xbox console settings have been uploaded, so these should be visible.
- Turned off and unplugged all devices, display cables and power cables, then reconnect all items after waiting 1hr+

- Verified that the same HDMI TV port and cable successfully display HDR 10 / Dolby Vision for my Apple TV 4K box (THIS IS NOT A TV OR CABLE ISSUE)

- Swapped HDMI TV port and cable anyway and tested xbox console to avoid being asked to do so later on.
- Unchecked/power cycle/rechecked all HDR/DV settings under 'general'>tv display options>advanced>video modes.
- Performed similar toggle and power cycle process for 60/120Hz, 1080p/4K resolution display settings to try and rule out a setting bug.
- Factory reset my console via the available console system setting menus.

- Launched multiple games to test both current generation and backwards compatability.

- Used the helpful onscreen signal information tool on my LG C1 OLED TV to confirm that the signal received from the Xbox console is only SDR, whereas my Apple TV 4K box supplies full 4K HDR/DV using the same HDMI cable & port.
- Connected my console to a friend's compatible TV and repeated all the same steps above with the same outcome.
- I have already received a phone call from Microsoft Xbox Support where we just repeated the same troubleshooting that I already performed listed above. No resolution was achieved or further support offered.
- There is a clear contradictory bug shown in the '4K TV Details' checklist where "HDR10 for gaming" and "Your TV supports Dolby Vision" is green ticked, but at the same time theres an error for "Your TV setup doesn't support HDR10 video. Content won't be shown in HDR".

- I have a STRONG suspicion that a recent firmware update that Microsoft pushed to consoles has broken HDR.

- If HDR functionality cannot be restored within a reasonable period of time, I will have to return my Xbox console under Warranty as it is not delivering the core performance features as marketed.

SIDE NOTE TO MICROSOFT/XBOX SUPPORT, SEPARATE ISSUE: There is a well documented (on this support website) and long term issue on the Xbox platform where there is a significant Audio Lag/desync/latency when sending audio signal via ARC/eARC. The audio lag is made even worse when the Dolby Atmos format is selected, but is present with all stereo/dolby formats that I've tested. Conversely, this issue is NOT present on other gaming consoles like Playstation. There has been zero response from Microsoft/Xbox support on this issue in numerous already-existing 'Ask A Question' posts now 1-2years old. Please acknowledge.

Console Model: Xbox Series X (connected directly to the TV HDMI 2.1 port)
Console Firmware: 10.0.22621.1836 (last updated 09 September 2022)

TV Model: LG C1 65inch OLED (HDR10, Dolby Vision, 4K 120Hz compatible)

Cable: Microsoft's OE supplied ultra high speed HDMI 2.1 cable with console














:)