Portable monitor on Mac Mini not detected

Solution 1:

I have had the same problem. I just upgraded to Catalina. I also updated my zen screen to the Catalina upload on the display link website. My monitor now starts when I start my mini Mac. However, I must make sure I turn off my Asus display when I shut down the computer, if I don’t Shut down the monitor it won’t start when I restart my mini Mac.