4k Resolution no longer works on mojave 10.14.6

thanks that actually works, but still doesn't show my native resolution. However i'm using hdmi right now, i am going to try a display port tomorrow and see if I have any more luck, thinking I may be limited by that (although it wasn't a problem before the update)

So I had been using an hdmi cable, this was limiting the amount of video bandwidth. I ended up grabbing a display port cable (display port to usb c in my case), and I was able to get a full 3840x2160 and a 60hz refresh, so windows were no longer laggy as well. After using that cable the full range of resolutions available (at a full 60hz) appeared again

I know. My only guess is maybe even giving the option to display at a lower refresh rate maybe it degraded performance. I do wish however it was more apparent as to how to change that setting, I would've never thought to option click that area to open that menu, doesn't seem super intuitive.

Here's the cable I bought though:

https://www.amazon.com/gp/product/B075V27G2R/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

Oh, and the major difference between 30hz and 60hz is at 30hz you're going to have a more noticeably "laggy" desktop experience. HDMI simply doesn't support anything higher than 30hz. Displayport does.

so I ended up using a free app called easyres to be able to select my native resolution again, and it's fine for now