I have a 27" Monoprice CrystalPro Display attached to my 2017 27" iMac. It's connected via USB-c/Thunderbolt to its DisplayPort input. Since the 12.3 betas, including the RC, my Mac no longer detects the display. However, if I use a different cable and connect to the display's HDMI port, it works as before. Hard to believe this issue hasn't been addressed in the beta yet.
blocktek
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