SolarWinds Software Engineer Internship interview questions

As a freshman student with several years of commercial experience, I have applied for a summer internship at Solarwinds. We have scheduled a phone call with an HR. It went fine; the usual questions. After that, I've been asked to send a written description of several projects I've been working on. My role, how it went, what I've learned and stuff like that. Then an onsite interview with 2 developers from the team that was hiring, and a different HR who was looking to fill a different position. We have started with my past experience. Then some tech questions. It was supposed to take 1 hour, but the conversation went well and we lost track of time a bit. When it was noticed the interviewer briefly went through several C# specific questions and the interview was over. In about 2-3 weeks I've received an offer.

Applied online and in a few days HR called back. Asked me a few background questions then appointed a meeting which I accepted. 3 hours before the interview, I knew I won't be able to make it on time and I will be an hour late so I called them and we rescheduled the interview to a MONTH later, and they said that since I rescheduled I will have lower chance of being accepted. Later that day they sent me an email saying they already took someone else. Not sure if the accepted person was so great or they just didn't care to interview me.