Vermietet.de interview questions

First interview: 1:1 video call with manager, where he asked me some standard design interview questions (describe your process, etc), and given some info about the company & role. I was then asked to complete a project to design an on-boarding flow for their tenant app experience. (red flag: design challenge looked suspiciously like free work for them) Second interview: After I completed it, I presented it to the manager and 2 other designers, who critiqued it, asked me further questions, and answered mine. They thanked me for presenting, and promised that whether I proceeded or not, they'd give me feedback on my homework in another call. I received an email after that which said that I wasn't proceeding, and did not receive feedback about why.