Hi Oliver Saxby
Welcome to the Microsoft Q&A Forum!
I understand how frustrating this is, especially when both monitors work individually.
What you’re seeing typically happens when the Dock struggles to negotiate both display signals at the same time. When one cable is removed, the remaining monitor initializes correctly, which is why each screen works on its own.
Things you can try:
- Use USB‑C to DisplayPort cables instead of HDMI where possible
- Avoid mixing cable types (for example, one HDMI and one DisplayPort)
- Use the same cable type and brand for both monitors
- Set both external displays to 60 Hz in Windows display settings
- Power‑reset the Dock: unplug everything (including power) for ~30 seconds, then reconnect power, monitors, and the Surface
- Make sure the Surface and Surface Dock 2 firmware are fully up to date
Let me know how it goes.
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