Emby v2.3.17 & RTX 5080: Automatic HDR not triggering (stuck in SDR output)

[ALLSTAR1986 17]

Hi everyone,

I'm having an issue with automatic HDR activation in Emby for Windows (version 2.3.17.2.0) on an RTX 5080 connected to a 4K HDR TV.

Setup & Working Features:

• GPU: Nvidia GeForce RTX 5080 (10-bit RGB Full)

• OS: Windows 11

• Emby Version: 2.3.17.2.0

• Working fine: 24p refresh rate switching and multi-channel audio passthrough work without issues.

Issue Details:

• No Native HDR Trigger:

  Even with Enable Automatic HDR Mode Activation checked, playing HDR content does not trigger HDR on the TV (output remains in SDR/UHD).

• Display Control Status:

  Under Display Control, it statically shows HDR: on. On my previous PC, this showed disabled by default and toggled to enabled only during HDR playback to send the native signal.

• Rendering Engines Tested:

  Both Hardware Decoding (DX11 Video Acceleration / RTX 5080) and Software Decoding output in SDR (internal tonemapping occurs instead of sending native HDR10 metadata).

• Minor UI Bug:

  The UI defaulted to English on clean install and had to be manually changed under General -> Display Language.

I have attached the log file below. Is this a known bug in build 2.3.17.2.0, or is there a specific driver/swapchain setting needed for the RTX 50 series?

Thanks for your help!

EmbyClient.txt