That's discomforting. My practice of sprinkling em-dashes like salt on a salad dates from my early days on various video game communities' forums. They comfortably mimic interrupted speech in writing. I hope I won't have to soon defend myself against accusations of AI usage just because I belong to the minority that read The Punctuation Guide[0] or a related resource.
It's really the em dash along with superfluous language. I suspect you are fine. Models like 4o have a very specific pattern when folks don't specify their writing style.
[0] https://www.thepunctuationguide.com/em-dash.html