macOS 26 misclassifies external USB keyboard connected via monitor USB hub as “Built-in Keyboard”

Since upgrading to macOS 26, external USB keyboards that are connected via the USB hub of a monitor are consistently misidentified as an internal (built-in) keyboard by macOS.

As a result, the system:

• Applies the wrong keyboard type (ISO/ANSI)
• Ignores the Keyboard Setup Assistant
• Uses incorrect key mappings and modifiers
• Does not allow the keyboard type to be reconfigured

The issue does not occur when the same keyboard is connected directly to the Mac.

Steps to Reproduce

1. Connect an external USB keyboard (e.g. Logitech G915 via USB dongle or cable)
2. through the USB hub of a monitor (USB-C or Thunderbolt monitor).
3. Boot macOS 26 or wake the system from sleep.
4. Open System Settings → Keyboard or try to launch KeyboardSetupAssistant.

Expected Result

• macOS detects the keyboard as an external keyboard
• Keyboard Setup Assistant is triggered
• Correct ISO/ANSI layout can be selected
• Key mappings work as expected

Actual Result

• macOS classifies the keyboard as Built-in Keyboard
• Keyboard Setup Assistant is not triggered
• Keyboard type is locked and cannot be changed
• Incorrect key layout and modifier mapping

This classification persists across:

• Reboots
• Sleep/Wake cycles
• Multiple different monitors

Additional Observations

• The issue occurs with different monitor brands and models
• It affects multiple external keyboards
• The problem is reproducible 100% of the time when using monitor USB hubs
• Connecting the keyboard directly to the Mac immediately resolves the issue
• Using an external USB hub (not built into a monitor) also resolves the issue

This strongly suggests a regression in the HID / USB device classification logic introduced in macOS 26, where monitor USB hubs are incorrectly treated as internal/embedded controllers.

Workaround

• Do not connect keyboards via monitor USB hubs
• Connect keyboards directly to the Mac or through a standalone USB hub

Impact

This regression breaks common single-cable monitor setups and makes external keyboards unusable or incorrectly mapped in professional environments.