Lower Resolution for Higher Refresh Rate

Hi Everyone,

So its pretty much as the title says but here is a bit of a background for clarification.

I have a 4k monitor and a 2017 Apple Macbook pro 13", this is the version of the macbook that has 4 usb c ports and they are the 2nd gen usb c ports (10 Gbps transfer speed). A 4k monitor requires at least 18Gbps up to function at 60hz. So this macbook cannot function with a 4k monitor unless you are content with a refresh rate of 30hz. I unfortunately cannot use the monitor at this resolution as it makes me feel nauseous over prolonged use, the slight ghosting and slower response rate just get to me for some reason.

What i have tried is lowering the resolution on the bigger monitor but it seems as if the resolution on a monitor is actually locked at its maximum and 'changing' it just results in scaling the gui. So no matter what 'resolution' you have selected, you will always get the 30hz refresh rate.

I have also tried holding option and clicking on scaled to expose other options but the same scaling occurs. I have tried selecting all the resolutions and checking in the refresh rate options but none of them offer anything above 30hz.

I assume that this is a hidden os setting or can be overridden via the terminal. If anyone could help with this it would be very much appreciated. Thanks in advance.