Canal interview questions

I had my first interview with Adam, I thought it went well. It seemed like he was trying to throw me off with some of his questions, it was intense and I didn't get any positive reassurance despite the fact that I answered everything well. He also didn't give me much info on salary which made it kind of weird. He ended up moving me to the next round which was a sourcing assignment. I spent about 4 hours on this assignment , and sent it over to him. At first I thought he may have not received it because I didn't hear any response. After following up over email a few times over the next few weeks I realized I had been ghosted. I've been a recruiter for many years, and I would never ghost a candidate that put over 5 hours of their own time into doing an assignment for the company. It takes less than a minute to write an email saying thank you for your time. It honestly made me wonder if they were trying to get free work out of applicants, he said he was really busy and needed support. I think it's a blessing in disguise I never had to work for someone like that.