Coherent Solutions Software Engineer Java Developer interview questions

Was interviewed for the position of Java Developer. The process started by a recruiter (maybe from a recruitment company), she contacted me, we scheduled a meeting so she could know more about myself. Later, they sent me some homework... yes, that type of thing. A small project in SpringBoot where I had to develop some REST API and deliver it to their team. I completed the task and sent it to them. I know, not too clever from me, as realized I just did free labor. After that, after some days, I asked for feedback. I tried at least 3 times in different until I got an answer. Their feedback was that my salary expectations were above their limit (they never mentioned their salary range) and that I am over-qualified for the job, even though the project was pretty small.