Looks like 144Hz max via HDMI is to be expected.I used the cable supplied with the monitor. The other HDMI cable I tried was indeed an older one but the one supplied surely has to be a new one.
From LG's page:
What res/Hz were you running your previous monitor at? Are you running a dual monitor setup, and if so, is this new monitor the primary or secondary monitor?
Also, does your laptop have a docking station? Sometimes you have to use the docking station HDMI connector to get the full spread of res/Hz options -- my wife's Dell work laptop is stupid like that.