Why doesn't Windows 10 give 2k resolution?

Question

Monitors

I bought a widescreen monitor 2k with a resolution of 2560x1080. But for some reason in Windows it is displayed as Full HD, the resolution is set correctly, but the display is disgusting. For an hour of work on it, the eyes simply begin to water. Pixels can be seen at a distance of 1 meter.
Nearby is a 4k monitor with a resolution of 3840x2160, and so on it in the settings, when choosing a resolution, there are items 4k 2k and so on. The other new one doesn't. Only full hd, and as I understand it, I now get a full hd image and not 2k at this resolution, so everything is blurry. Who can tell? Installing the driver from the disk did not help.