Hi Graham Blair, thanks for the detailed breakdown. Based on your steps and system specs, here are a few additional suggestions that have helped others.
First, try switching to the older Windows 7/8 Focusrite driver (version 3.6.0). Several users have found this more stable than the latest Windows 10/11 drivers. Before installing, do a clean uninstall: unplug the device, remove all Focusrite entries from Device Manager (enable “Show hidden devices”), uninstall Focusrite Control and drivers from Programs, then reboot and install the older driver.
Second, check your USB connection. Avoid hubs and adapters connect directly to a USB port using the original cable or one that meets Focusrite’s specs. Try different ports, especially USB 2.0 vs. 3.0, as performance can vary.
Third, increase your buffer size in Focusrite Control to 1024. This can help reduce dropouts and improve stability. Also, disable Windows Spatial Sound and background enhancements in the sound settings, as these can interfere with audio routing.
Lastly, consider disabling automatic driver installation in Windows to prevent it from overriding Focusrite’s drivers. You can do this via Group Policy or Device Installation Settings.
Let me know if you'd like help walking through any of these steps happy to help.
If you found the response helpful feel free to mark my answer as helpful/accepted, it might make it easier for others to find the solution too.
Best,
Carl