Thanks for reaching out to us, I am sorry to hear this is not working as expected.
Our expected behavior with our UD-CA1A docking station and Thunderbolt 3 MacBook Pro systems is the external display should be detected when the system is powered on or waking from a low power state and show the desktop background while logging into the computer.
The UD-CA1A USB-C docking station does not utilize the DisplayLink software, this docking station takes advantage of the computer’s Thunderbolt 3 Type-C DisplayPort Alternate Mode, a direct connection from the computer’s graphics processor to the Thunderbolt 3 port, and across the USB Type-C cable to the docking station.
I would like to start off by getting some additional details on the process that reproduces this behavior to start narrowing down the possible causes of this behavior, when you have a moment please let me know the following:
- Is the docking station connected with the original USB-C cable or using a cable from another manufacturer or product?
- Does the display go offline when the computer is restarted, or powered off and powered back on again? Or is this only happening when the computer is left idle and enters the sleep state?
- When the display is working, does disconnecting the docking station from the computer then reconnecting the docking station cause the display to become undetected or does it work as expected?
- When the display goes off, does restarting the system ( but not unplugging power from the docking station ) restore the display?
Thank you for these additional details, they will help to determine our next steps.