Altec Industries interview questions

Received an email asking about my interview availability within a week of applying for the position. Two people interviewed me, both of them were respectful, chill, and overall very nice to me, especially considering I was very nervous and it was my first real interview. They asked me about my previous work experience (I have only had two jobs), and they asked about common challenges I faced in those roles, what my typical day looks like for them, and the general work for them. They asked about a couple specifics off my resume, and asked about which department I'd be comfortable in. I even made a small joke about a number I used on my resume that was slightly inflated, but they laughed with me about it and it was nice that they weren't taking it TOO too seriously. Still a very professional space and process but it was definitely more chill and welcoming than I was expecting.

Applied online. HR contacted me via text a few days later to setup phone screen. Agreed on time and had a good conversation that lasted an hour. Seemed like strong alignment and HR inquired about my availability for an interview with the hiring manager the following week. Sent a follow up thank you the next day and got no response. Week came and went as did a second week. Sent a final message to see if there was interest in the interview still. Ghosted... I understand things happen and I was fine but the abrupt change from rapid engagement to ZERO is not professional