Siemens Developer interview questions

The first phone interview is pretty good. Common HR questions. A few basic technical questions. The second technical interview was extremely vague, was really difficult to understand what they wanted to check by asking such questions. It was a coding test. They described me a problem, I started to think out loud. Then they stopped and said "no let's think about the following"...okay. I started to describe my thoughts. Then again they said "let's think about another thing"...we switched again. Then we got back to the first original problem. So we jumped over different topics. All that looked like they wanted to pay attention to everything but in reality it was about nothing. After the interview, you cannot answer yourself such questions like what was it? What did they want you to do? The problem is so simple, why to make this mix of questions, ask about everything in the same moment of time? I think you should have the talent to turn such simple task into such a big problem so that it's difficult to understand what you want.