It was a Zoom interview with two people, someone from HR and the person who is currently, or previously had been, in the role I was applying for. The HR person set the tone and explained the basic setup with introductions, background questions, and a behavioral question.
Since this was my first interview in many years, I didn't quite understand the concept of the "behavioral interview." Later, I worked out that they were probably looking for me to show my analytical skills by asking me questions that had faulty assumptions or what they deemed difficult real-life scenarios. I answered them in a straightforward way and thus sealed my fate. Lesson learned, too little, too late.