Hi LY_9,
Thank you for reaching Microsoft Community. I understand that both of your newly purchased Thunderbolt 4 docks are not working with your Surface Laptop 4. I'm sorry for the inconvenience this has caused you.
There are a few possible reasons why your Thunderbolt 4 docks are not working properly. Here are some steps you can try to troubleshoot the problem:
- Update the Surface Thunderbolt 4 Dock using the downloadable MSI package. Go to this page then select the SurfaceThunderbolt4DockDrivers_Win11_x64_22000_23.033.35236.0.msi file: Download Surface Thunderbolt 4 Dock Firmware and Drivers from Official Microsoft Download Center. After downloading, run and install the file. (Update your Surface Dock - Microsoft Support)
- Check the video cables and adapters you are using to connect your Thunderbolt 4 docks to your external monitors. Make sure they are compatible with Thunderbolt 4 and have the right specifications. For example, if you are using an HDMI cable, make sure it's rated version 2.0, or, if using a DisplayPort cable, it's rated 1.2, and is no more than 6 feet (1.8 meters) long.
- Reset the dock by following these steps below: (Troubleshoot Surface Dock or Surface Docking Station - Microsoft Support)
- Unplug your Surface Dock from the power connector on the back of the dock.
- Reset the dock PSU by unplugging it from the power outlet and waiting 5 seconds.
- Reconnect the power connector to the dock, then plug the dock PSU into an electrical outlet.
- Avoid plugging or unplugging your Thunderbolt 4 docks when your Surface Laptop 4 is entering or resuming from a power state such as Modern Standby, Hibernate, or Soft Off. This may cause the devices connected to the docks to stop working. For more information, see: Devices connected through a Thunderbolt Dock stop working - Windows Client | Microsoft Learn
If still issue persists, please try clearing the display cache of the Surface. See this page then refer to Solution 9: Troubleshoot connecting Surface to an external display - Microsoft Support.
Let me know how it goes.
Kind regards,
Marrion