Hi Richard,
Can you check if any of the Windows updates has caused the problem? We know that sometimes Windows updates has an influence on the MST Hub behavior.
This is from Jan 16th updates
Intel(R) HD Graphics Family driver update (v10.18.14.4029)
- Adds support for the Autodesk Mudbox 2015 paintbrush tool.
- Ensures that unreadable text does not appear in the Microsoft Outlook calendar pane.
- Improves performance of video display and zoom features in DirectX applications
- Adds support for the fast cursor feature when using Miracast adapters, including the Microsoft Wireless Display Adapter.
- Ensures there is no flickering/blank display on externally connected monitors, especially when connecting multiple monitors in a daisy-chain configuration
- Improves compatibility with Samsung U28D590D and Dell 2713Hb monitors. Some customers reported they saw a change in screen resolution when the device is docked and connected to Dell monitor. This has been addressed in the update.
- Adds additional support to enable better compatibility with Panasonic and Actiontec Miracast adapters
- Ensures there is no unexpected battery drain while the Surface device is in Connected Standby mode.
- Resolves KMODE_Exception_Not_Handled system crash when using Excel PowerMap
- Resolves some instances of Stop 0x9F and Stop 0x133 system crashes.
- Resolves system hang that could occur if f.lux was enabled by an application.
- Resolves system crash that could occur when attaching to external monitors immediately after waking the device from sleep or removing it from the docking station.
Marvell Wireless Network Controller and Bluetooth driver update (v15.68.3073.151)
- As part of ongoing improvements to Wi-Fi experience on Surface Pro 3 device, customers now have the ability to manually select a preference between 2.4 GHz and 5 GHz connections for their device. We will publish a separate blog to describe this functionality further so more customers can take advantage of this capability.
- Modifies power management logic to allow the wireless adapter to function properly when the Hyper-V feature is enabled in Windows.
- For European Union customers, there are specific requirements outlined in EN 300 328 v1.8.1. This update includes capabilities to stay current on these requirements, including an LE switch to better control energy detection and Bluetooth Power setting.
- Resolves a low throughput scenario when using Cisco 3702 access points in 11ac mode.
Surface Home Button driver update (v2.0.1179.0)
- Improves compatibility with Surface Hub application.
Surface Integration driver update (v2.0.1182.0)
- Improves compatibility of Surface Pro 3 with Windows 10.
Microsoft Docking Station Audio Device driver update (v1.31.35.7)
- Addresses scenario where no sound would play while the device was docked without an external speaker connected.
Here are the latest update packs for Surface
Also note