Ethernet not showing connected on MacBook Air M1

I have a UD-3900PDZ connected to MacBook Air M1. Everything is working fine except for the Ethernet cable. I have it plugged into the back of a Linksys SE2800 Switch connected to a router. The cable is also connected at the other end to the UD-3900PDZ dock. All lights (green and yellow) are working showing activity at both ends and I can even see the pluggable device through my router admin page with an IP and MAC address indicating that it is connected to my network.
However, when going into the network settings of the Mac, it only shows wi-fi connectivity and indicates the ethernet cable is unplugged. If I turn off wi-fi, I have no network connectivity.
I have even tried switching between DHCP and manually assigning an IP in the Mac settings. In neither case does the Ethernet get detected.
I have only had the device for a few weeks and the ethernet originally was detected. not sure what happened now that causes it to show as unplugged.


Thank you for contacting us, I am sorry this is not working as expected and I am happy to help!

Based on your description I would like to start by resetting the docking station and computer to see if this helps to restore the functionality, please perform the following:

  1. Disconnect the docking station from the computer and remove the power connection from the back of the docking station, unplug all USB devices from the docking station
  2. Disconnect the docking station’s power supply from the wall and let both the docking station and power supply sit for 30-90 seconds to fully discharge
  3. Restart the computer: Apple Menu > Restart
  4. After 30-90 seconds, reconnect the power supply to the wall socket or power strip
  5. Reconnect the power supply to the docking station
  6. Reconnect the docking station to the computer using the original USB-C cable provided with the docking station
  7. Check for the external displays to be detected on the system, if they are not detected please let me know
  8. Reconnect the network cable to the docking station and check for macOS to detect the Ethernet connection
  9. Reconnect any other USB devices to the docking station after verifying the network is either a) working, or b) not working

Please let me know if this helps, if not we can go from here.

Thank you,


This topic was automatically closed 20 days after the last reply. New replies are no longer allowed.