Same here - Intel Mac mini 2018 fully working on USB3/DP adapter and cable to Samsung 49" Upgrade to 12.3 and it is ruined - horribly quality control by Apple. Any attempt to get it working fails. Inserting both HDMI and USB3/DP adapter+cable actually works after boot. Remove HDMI and USB3/DP adapter remains fully working. Reboot and the display is activated, but nothing displayed - black screen (monitor reacts differently if there is no input) Insert HDMI again and it might work and I can switch to HDMI input on the monitor. Removal and HDMI in this state and the MacOS kernel panics, crash and reboot... Have tried 2 difference USB3/DP adapters and a direct point-to-point USB3/DP cable - same result. Display on HDMI will either work and scale fine on boot - or - display a weird mini-version in a higher res in a weird form factor MacOS 12.3 is outright customer-hostile upgrade breaking existing working systems.