External display image washed out on MacOS

JakeIsBacc · November 12

Hey all, I've got a strange problem and I've spent a lot of time trying to figure it out, but to no avail. Now I'm wondering if any of you could help me out. Here's what's going on:

When I connect my external display to my MacBook directly through an HDMI cable, the picture on the external display looks super washed out and terrible. Doing so also enables 100hz.

However, when I connect the same monitor and same HDMI cable through a crappy usb c adapter, the picture looks absolutely perfect, albeit only at 60hz.

My theory is that MacOS believes the monitor is HDR, and so is feeding it an HDR signal, but obviously can't do so with the crappier adapter. No matter what, I never see an option for HDR in the display settings where it should be.

The monitor is 1080p and does not support HDR

Extra info:

MacOS Sequoia 15.1

Monitor: KoorUI N02

Changing the refresh rate does change anything either.

There seems to be an option on the monitor for DCR, which I thought might be causing problems, but it is disabled and changing it doesn't seem to make any difference.

This problem doesn't seem to happen when connected to a windows laptop.

Please let me know if any other info would be helpful.

Thanks in advance