Issue with External OLED Monitor on Asus Laptop (Lid Close + HDR Problems)

[DamienSA]

Hi all,

I’m running into a strange issue with my Asus laptop after connecting a new OLED monitor, and I’d love some guidance on what might be causing it.

What happened initially:

• When I first plugged the monitor into the HDMI port, everything worked fine.

• I was able to close the laptop lid, and the monitor continued displaying (duplicate/extended mode worked without problems).

What changed:

• I went into Windows display settings and enabled HDR on the laptop’s built-in display (and possibly changed a few other display settings).

• After doing this, I could no longer close the laptop lid without the external monitor losing signal.

• I confirmed that my Windows power settings are set to “Do Nothing” when the lid is closed, but that didn’t help.

What I tried next:

• Pressed Windows + P and selected “Second Screen Only” to see if that would fix things.

• That actually made things worse:

  • The laptop display started bugging out (flickering on/off).

  • Sometimes it would only show a solid pink/purple screen (the same accent color as in the settings window).

  • This only happened when the monitor was connected via HDMI, and stopped as soon as I unplugged it.

Temporary workaround:

• I connected the monitor through a USB-C → HDMI adapter instead of the laptop’s HDMI port.

• With this setup, things went back to normal: I could close the laptop lid and use the external monitor as the only display.

New problem:

• After re-enabling HDR again, the issue has returned: now I can’t close the laptop lid without the external monitor shutting off.

• The monitor still works otherwise, but I’d really like to figure out what’s breaking the lid-close functionality.

My question:

• What could be causing this? Is HDR interfering with the laptop’s display handling over HDMI vs USB-C?

• Is this a driver issue, a Windows setting conflict, or possibly something Asus-specific?

Any help or ideas would be greatly appreciated!

[Falcon2_ROG]

@DamienSA 
May I ask for the full model of the laptop you are using?
[Windows 11/10] How to check the model name and BIOS version
Since it’s unclear whether your subsequent settings may have affected the driver, we recommend going to Device Manager to uninstall the graphics driver, restarting your laptop, and then reinstalling the graphics driver to verify. 
Sorry for any inconvenience it may be caused. 

[DamienSA]

Thanks for your reply! It definitely feels as though I have corrupted the driver somehow. 

As of last night, my laptop is now reading my 27" OLED monitor as an LCD, limiting its resolution and refresh rate and overall display quality to that of an LCD, it now literally looks like an LCD display from back in the day. This happened for seemingly no reason other than fiddling in display settings and trying to troubleshoot the original problem. 

I will try reinstall drivers and report back

[DamienSA]

The main issue I was trying to solve initially was to only display on my Monitor as my laptop screen is on its way out (it has 3 black lines running horizontally across the task bar) and I bought the monitor so that I could give the screen a rest with the lid closed as I will only be able to send my laptop in to the agent for warranty repairs in December as I need it for work. I wonder whether these lines/screen issues aren't in any way the root cause of all the other issues I'm now experiencing. I sure hope not. Any insight would be greatly appreciated

[DamienSA]

Update: I figured out what the issue is..... My laptop only has HDMI 2.0 which seemingly doesnt support running HDR at 120Hz.... so when I have RR set to 120Hz and activate HDR, it causes my screen to bug out and flicker and causes some sort of corruption of the settings. This renders HDMI port useless. I fixed this by using a different HDMI cable which seems to reset the configuration back to normal again, provided I dont try activate HDR at 120Hz. Seems to be one or the other, but not both at the same time.