Is this a red flag?

I applied for an 8 week summer internship. I was really excited about it but I’m starting to wonder if the company is a little unprofessional?

For starters, there were two positions open. I applied a week before the closing date, did the first round of interviews, and then a week after my interview I heard back from the interviewer. She said that the company had actually already hired someone by the time I applied and they didn’t communicate that to her until just then. They also closed one of the positions, so they were no longer looking for anyone. I thought it was really weird to hire someone before the application even closed. And to not communicate that to the people processing the applications.

Anyways, the interviewer sent me a couple more similar internships that she thought I’d be a good fit for. She told me to pick one and that she’d send my packet to the manager. I chose one and I heard from the manager almost immediately. He wanted to schedule an interview.

For the past two weeks it’s been a cycle (over email) of him suggesting a day, me responding with my availability that day, and then not hearing from him until after that day has already passed. It’s happened 4 times already. Yesterday we finally actually scheduled an interview. It’s supposed to be in an hour and I still haven’t received a link to a video chat or even a phone number. I emailed him about an hour ago to confirm the interview and get a link and I haven’t heard back.