Laptop not offering correct resolution for monitor (ultra wide)

[413x]

Not seen this before.

My work laptop doesn't seem to offer 'wide' resolutions.
I have max res of 3840*2160 offered

But I have 3440*1440

So the res offered is above this. So doesn't feel like a cable spec/port issue

Cable is dp (laptop end) to hdmi (kvm end) so maybe its this?
Not an issue for my surface book though

 

[Diagro]

Make a custom res