LG Monitor doesnt recognize macbook air

My macbook air recognizes the display, i can see it in the systems but the monitor shuts off as it cannot detect a feed. I tried the hdmi port and dvi port with same negative results. I tried two other macs with the same result, however when i hook up a roku or a windows pc it works fine, so i know its not the cables, and since the mac laptop recognizes the monitor, i know its not the computer either. I have updated to latest os release 10.15.4

any suggestions?