Wise interview questions

Two rounds of skype interview, an executable task of A/B testing 9 pgs long :( Two rounds personal interview one with the team one with other product guys I think with peers. After 4 rounds where it was clearly stated that there is no right or wrong answer, they are just curious, I have asked after every round direct and immediate feedback from the interviewer. In the last round I did the same they said that they do not know what they are looking for. Most of my answer was clearly demonstarted my outside of the box thinking. Yet the refusal letter was referring that I was not thinking enough ourside the box. It is clear BS.