21:9 Resolution 2560x1080p

Hello,

I have a problem for which I hope someone will have a solution. I've searched everywhere and haven't found a resolution to my issue.

I already had an LG 21/9 screen with a resolution of 2560x1080p 25" which is no longer available on the market (too old) => https://www.ldlc.com/fiche/PB00195781.html

I had a second screen with a standard resolution and I decided to replace the second one with the new version from LG to have two screens with the same 21/9 resolution of 2560x1080p => https://www.ldlc.com/fiche/PB00214720.html

The only problem is that in the Windows display settings, the recommended resolution for the new screen is 1920x1080p and 2560x1080p is not displayed as an option, while it is available for the first screen.

First screen: https://img15.hostingpics.net/pics/903301962.jpg
New screen: https://img15.hostingpics.net/pics/702119801.jpg

I find myself with a 1920x1080 screen that gives a flattened rendering and a 2560x1080p screen that provides a perfect rendering in terms of proportions.

When I turned on the new screen for the first time, a message from the screen appeared, telling me that the resolution was not optimal for the screen, which should normally be set to 2560x1080p and that some PCs might not support this new resolution, setting it to 1920x1080p by default.

But I imagine that since I was able to have this resolution on one screen, it doesn't come from my PC?

EDIT: I'm not sure if this could be the issue, but the new screen is connected through a DVI=>HDMI adapter because my computer only has one HDMI port taken by the first screen.

Thank you for your help.