Is it a M1 chip?
We’re having the same issue with picking refresh rates which I think is linked to something quirky Apple is/isn’t doing on the M1 chips.
My 2018 MacBook Pro works fine, can select refresh rates… M1 Mac Pro doesn’t see anything, M1 MacBook Pro only lets you see 30/60hz but is flaky displaying anything ‘if’ it decides to see it. So the only option would be to have a scaler up/down convert it (Like blackmagic UpDownCross converter) but I haven’t tested if that solves the issue yet since I don’t own one and as they are now, unlikely to every buy one!
“By the book…”
Yeah, lets wait and see because nothing apple touches is by anything but apples book! But then the whole USB C shambles is such a mess its hard to know if its crappy cables or companies being aholes because my ipad will charge with 1 cable, but not another, yet both charge my pixel fine.
But then i’m not spending £ks on an iPhone anymore when they seem to be following google’s book and have separate departments that never collaborate so you get garbage software! 😡