I recently bought the UD3900H and set it up with my M1 IMac 24". I downloaded the latest drivers (1.8), however when connecting both my external displays, one the displays gives a black screen. I tried swapping the HDMI port between the DVI → HDMI adapter and the traditional port but the same screen stays black. I can see the OS and the DisplayLink Manager detecting the monitor. Also whenever I go to my Display settings in System Preferences, the external monitor is turned 90 degrees by default despite setting it to standard in the DisplayLink Manager. I’ve tested the display with another generic usb-c to hdmi adapter and it works fine. I would really like some assistance with this.
Monitor 1: LG Ultragear - no issues
Monitor 2: HP 22cwa - monitor having issues with dock