I have an Acer XF240YU 23.8" ( https://www.scan.co.uk/products/238-acer-xf240yu-2k-freesync-monitor-144hz-2560x1440-1ms-350-cd-m2-100m-1-dp-hdmi-dvi-black-red) monitor and in the user instructions it clearly says I need a displayport or HDMI 2.0 to reach 144Hz at 2560 x 1440 resolution. I bought a HDMI 2.0 cable (https://www.amazon.co.uk/dp/B00NQ9OQU2/ref=pe_1909131_77697121_tnp_email_TE_AMZLdp_1) and plugged it in today only to find it still capped me at 70Hz in the monitor settings! Please help - should I just by a display port?