Sometimes external keyboard does not trigger MonitorControl

Before opening the issue, have you...?

• Searched for existing issues
• Looked through the wiki
• Updated MonitorControl to the latest version (if applicable)

Describe the bug

I have MonitorControl set to use "Standard keyboard brightness keys" and "Screen to control" set to "Depends on mouse pointer position". But whatever I do, when I use the brightness keys on my external Apple wired keyboard, it is always the internal MacBook display that is changing brightness.

However, when I use the keys on the MacBook keyboard, everything works as expected and MonitorControl does its thing.

This is a somewhat new bug (maybe a few months?) It used to work well with the same hardware.

Steps to reproduce

Press brightness keys on external wired Apple extended keyboard while mouse pointer position is on the external display.

Expected behavior

Brightness is changed on external display. Actually happens: brightness is changed on Macbook internal display.

Anything else?

No response

Environment Information (please complete the following information)

- macOS version: Sequoia 15.5
- Mac model: M2 MacBook Air 2022
- MonitorControl version: 4.3.3
- Monitor(s): Dell P2720DC
- Apple Silicon/M1 (yes or no): yes

Start by reproducing the issue with the stated MonitorControl settings, macOS version, keyboard, and external display. Trace how external keyboard brightness events select a display based on mouse pointer position; done means the external keys control the display under the pointer while the MacBook keys retain their expected behavior.