Hello JamesKitching1,
Thanks for reaching Microsoft Community. We're sorry to hear about this external display issue on your device. We'll do our best to help.
This could be due to display driver problem or software conflict resulting your device not to recognize the external monitors. In the meantime, please give these methods a try and observe if issue persists or not:
- Run the Surface Diagnostic Toolkit and check for Windows Update. Ensure all pending updates are installed.
- Manually install drivers and firmware for SurfaceCheck what is the current OS Build of your Windows version by typing winveron the search barnear the Windows logo.
Go to Download driver and firmware for Surface**,**choose (your Surface model) then click **Download.**Choose the .msi file closest to your current OS Build and click Next.
After downloading, run and install the .msi then Restart. - Run the System File Checker in Windows (microsoft.com)
Kindly also follow the troubleshooting guide on Troubleshoot connecting Surface to a second screen (microsoft.com) and Troubleshoot Surface Dock and docking stations (microsoft.com).
Feel free to respond on this thread to let us know how it goes.
Hope to hear from you.
Kind regards,
StevenK