Newton Crypto interview questions

The process is pretty standard, but a couple of weird points. 1. The recruiter reached out by phone instead of email, and jumped right in to it because I had time. This was a first for me personally. 2. There is a time boxed 3 hour case study. I didn't mind this that much. What really ended up leaving a bad taste was the lack of communication after this. After about 4 days since submitting, I typed a follow up email just to check up. They got back to me a week later with a "we'll follow up next week". That was the last I heard from them. I know its standard for PM interviews to include case studies, but if a candidate does submit one then I think it should be common courtesy to at least follow up. Especially given the candidate invested time.