1. Please try unplugging the dock from your computer and disconnecting all devices from the dock for at least 5 minutes. Afterward, reboot your laptop and reconnect the dock to see if this resolves the issue.
2. Try the device with a different laptop that has a C port and the C port supports DP Alt Mode.
3. Make sure that you have used the included USB C to USB C 3.2 Gen2 cable to connect to the laptop.