How a BBC navigation bar component broke depending on which external monitor it was on

Recently, my team and I fixed an absolutely bizarre bug that only one person in the team could reproduce. And to make it even weirder, she was only able to reproduce the issue when using her work laptop at home; it worked fine with the same laptop in the office. So what was the bug? The BBC's UK website uses a click event to respond to when a user activates the 'More' button. click events aren't…