Phoseon Technology interview questions

I received an email from a supervisor inquiring about setting up an interview. I replied back with delight and outlining my availability for the next several days. I was then completely ghosted and didn't hear back from them. Either a firewall in their email blocked my reply or they are just unprofessional. I don't know which is true.

There was two phone screens and one on site interview. The first phone screen was with a recruiter, then the second was with the reliability manager. Then there was an on-site for two hours that included a one on one as well as two separate talks with the engineering VP and the current mechanical engineering staff.