4k working great, but ultrawide not?

[Kaboz]

Gents,
I'm in a very weird situation.

2 of my laptops (Windows and Mac) are working perfectly with 4k TV's but sub-par with ultrawide monitors.
The ultrawide monitor is the Samsung C34f791, and I also tried with Samsung S34E790 and the results were the same (or slightly worse)

Here's what I've done:

1) Connect Lenovo yoga900 (i7-intel 520 gfx card) or Macbook pro15 2018 (i7- AMD Radeon) to the ultrawide monitor: Colors are washed out, foggy/blurry and lack saturation (3440*1440 @100hz and tried to downgrade to 50 and 60hz, same problem).. using Anker usb-c to HDMI adapter and HDMI 2 cable

2) Connect T470p or PC to ultrawide monitor: works perfect, and Colors are stunning (3440*1440 @100hz).. using the same HDMI 2 cable

3) Connect the yoga900 or Macbook to a 4K 55inch TV: perfect, colors are stunning (4k@60hz) using the same Anker usb-c to HDMI adapter and HDMI 2 cable

I don't know what to make of this, can someone please help ?

 

[pp111]

I am just wondering if this is an HDR misconfiguration. Have you tried disabling HDR in the laptops?

 

[Kaboz]

The Monitor does not support HDR: https://www.rtings.com/monitor/reviews/samsung/c34f791-cf791
For Macbook, I opened display settings and the HDR option wasn't displayed (which means the Mac detected its not hdr)
Fpr Yoga, I went to display settings --> Windows HD Color settings, and I found the video, games and apps HDR settings marked as NO

 

[Kaboz]

Ideas anyone?