How to make the monitor work at native resolution?

Question

Cables and wires

Hello!
Help with solving the problem. There is a Lenovo X250 laptop with a mini Display Port video output, and an LG monitor (2560x1080) with an HDMI video input. I'm trying to connect the display with a mini DP to HDMI cable - I'm faced with the fact that I can't set the monitor's native resolution. I tried a couple, an adapter from mini DP to HDMI, and an HDMI-HDMI cable to it - the same thing, do not set the native resolution.
I tried to connect another monitor with the same resolution but with a Display Port input, everything works like a clock.

Answer 1

The root of the problem is in the miniDP -> hdmi adapter, get rid of this strange signal conversion (maybe this creates a problem), for example, change the monitor to one with dp.
The intel hd graphics 5500 graphics card is capable of outputting:
those. 2k will be hard up to 50Hz, maybe the monitor can't play low framerate resolution

Answer 2

the mini DP + HDMI pair now outputs a maximum of 1366 by 768.