Arcosa interview questions

We had a phone interview and within a few days, I was scheduled for a face to face. I was 4 hours away so had to take off from my primary job as a welding instructor.. Face to face was supposed to include 3 people and I thought it would be a discussion and tour but instead was a meeting with one person in the office and another in the shop during a tour. It was a great tour and I felt good about the interview. The HR person wasn't present as she had to go on vacation. Yet it seemed urgent I get there quickly. We drove back and I got a call the following week saying they were going to make an offer but needed a start date. I teach a night program so I wanted a sufficient time to not leave my students hanging. I told them the earliest would be 2 months BUT it was possible it could be faster if an offer was satisfactory and my institution could get a replacement. The HR person texted me back with a "how about 15 June....I responded that it was doable. That was on 6 May...I never received an offer. Followed up with them by email a few days later and they indicated it was taking more time because of HR. Today is 29 May and no follow up. They did indicate they had gone through some HR folks.