I can't get the resolution on my 2017 iMac as 2nd monitor to not be fuzzy

has anyone else dealt with this? the correct resolution 2560 x 1440 says (low resolution) after it.. mirroring an M2 MacBook Pro.. ive tried usb-c to usb, lightening 3 cable, hdmi to usb-c (that says its Mac monitor compatible.. ) nothing works.. it always says (low resolution) on a bunch of the resolution options.. halp!