Not sure if it makes a difference but I also enabled flexible scaling using betterdisplay.I was finally able to upgrade my M4 Pro mini to Tahoe yesterday. I've always had 3200x1800 and 3360x1890 as HiDPI options for my U3224KB, but don't see new options like 3840x2160 under Tahoe. Not a big deal since I like 2:1 scaling anyway. Just interesting. I wonder if it has something to do with me having the 12 core and you having the 14 core version of the Pro M4, or the KB (not KBA) monitor, or the mini vs mbp.