Windows 11: Bluetooth keyboard sends duplicated characters only while a bus-powered USB 3.0 external SSD is connected to the same hub

Environment

Surface Laptop running Windows 11 22H2 with built-in Bluetooth adapter; Bluetooth mechanical keyboard (Logitech K380) paired via Windows Bluetooth stack; external bus-powered USB 3.0 NVMe enclosure connected to same USB-C hub as the laptop charger; problem observed on two different hubs and two keyboards.

Symptoms

When the external SSD is connected and in active use (file copy in progress), typing on the Bluetooth keyboard intermittently produces duplicated characters (e.g., 'tt' instead of 't') and occasional missed keystrokes. The issue stops immediately when SSD is unplugged or when file copy completes. Mouse input over Bluetooth does not appear affected.

Observations

• Windows Event Viewer shows no kernel errors for Bluetooth adapter. - Device Manager shows Bluetooth adapter module using Microsoft driver; no updated OEM driver available. - USB enumeration shows external enclosure connected as SuperSpeed 5Gbps device. - Moving the SSD to a separate downstream port (different hub) reduces duplicates but does not eliminate them. - Disabling Bluetooth power saving (Device Manager -> Bluetooth Adapter -> Power Management: uncheck 'Allow the computer to turn off this device to save power') reduced frequency but did not remove the problem entirely. - Replacing the SSD enclosure with another model (USB 2.0 UASP vs USB 3.1) changed behavior: one enclosure stopped causing duplicates, the other reproduced it reliably.

Already attempted

• Updated Windows and Bluetooth drivers via Windows Update and vendor site; issue persisted. - Tested keyboard on same laptop when SSD is connected directly to laptop USB-C without hub: duplicates still occurred during heavy writes, though less often. - Changed keyboard battery and replaced with fresh cells. - Disabled Wi‑Fi temporarily (to rule out 2.4 GHz interference) — no change. - Ran Windows Bluetooth troubleshooter (built-in) — no actionable change. - Tried a different Bluetooth keyboard/headset: same duplication observed with second keyboard model.

Question

Why does a bus-powered USB 3.x NVMe external drive being actively used cause duplicated keystrokes on a Bluetooth keyboard connected to the same host, and what reversible mitigations can I apply to stop the duplicates without replacing major hardware?