Dell OptiPlex 3060 SFF – HDMI works in Linux but is unavailable in Windows

Hello,

I have a Dell OptiPlex 3060 SFF with an Intel Core i5-8500 and Intel UHD Graphics 630.

I am using two identical LG FHD monitors:

• one connected directly to the motherboard HDMI port;

• one connected directly to the motherboard DisplayPort.

The problem is very specific:

Linux detects and uses both monitors simultaneously without any problem, while Windows detects only the DisplayPort monitor.

Under Linux:

HDMI-1 connectedDP-1   connected

Both monitors work at 1920×1080 @ 74.97 Hz. The HDMI EDID is read correctly from /sys/class/drm/card1-HDMI-A-1/edid, and the HDMI connector reports connected with a Good link status.

Under Windows, only one monitor is active:

DISPLAY\GSM5BCA\4&e05c5b5&0&UID200195_0VideoOutputTechnology : 10

This is the DisplayPort-connected LG.

Windows PnP also sees the LG monitor when the HDMI cable is physically disconnected and reconnected, but it does not become a second active display.

I tested the following:

• Intel UHD 630 driver 30.0.101.1692;

• Intel UHD 630 driver 31.0.101.2137;

• complete removal of the Intel display driver and clean installation of 31.0.101.2137;

• Windows 11 23H2;

• in-place upgrade to Windows 11 25H2;

• BIOS update from 1.15.0 (2021) to 1.32.0 (2024);

• swapping the two identical LG monitors between the HDMI and DisplayPort outputs;

• physically disconnecting/reconnecting HDMI;

• PnP hardware rescan;

• clearing the Windows GraphicsDrivers\Configuration display cache;

• DisplaySwitch.exe /extend;

• DisplaySwitch.exe /external;

• complete power removal from the PC for about 30 seconds.

None of these changed the behaviour.

The Intel UHD 630 itself reports no device error:

Status                 : OKProblem                : CM_PROB_NONEConfigManagerErrorCode : CM_PROB_NONE

The current Intel driver is:

31.0.101.2137

BIOS is:

1.32.0

Windows QueryDisplayConfig reports an HDMI target:

Target ID        : 198195OutputTechnology : 5TargetAvailable  : 0

So Windows appears to know about an HDMI target, but considers it unavailable.

dxdiag also reports only the DisplayPort monitor:

Monitor Model: LG FHDMonitor Id: GSM5BCAOutput Type: Displayport External

The important point is that the same physical HDMI port, cable, and monitor work correctly under Linux on this exact machine.

Could someone from Dell explain what could cause the onboard HDMI output of an OptiPlex 3060 SFF to be detected by Linux but remain unavailable in Windows?

In particular, I would like to know whether there is a known issue involving the OptiPlex 3060 motherboard firmware, Intel UHD 630 display output configuration, or the HDMI controller that could produce this behaviour.

Any Dell-specific diagnostic procedure or known workaround would be appreciated.

Thank you.