Monarch Steel interview questions

Was solicited through LinkedIn by the operations manager, who was in search for a quality manager needed in their Decatur, AL facility. Had a lunch interview which went very well and we both agreed we were interested in me taking the role. I was advised that the executive adviser would want to do a phone interview also, and a week later that occurred and went very well. One week following that, I received a phone call from the operations manager with an offer which I accepted, pending salary negotiations. We scheduled another lunch meeting for the following week where I met the new customer service manager as well. We all discussed benefits and the entire compensation package. I was told they were excited to have me join their team and that I'd receive an official offer letter the next day, since they would collaborate together on what salary to offer me. I never heard anything from them again. I waited a week and reach out via text and LinkedIn to reaffirm my interest in the position and requesting a status update on the offer letter. After no response for yet another week, I called the operations manager and it went to voicemail. My phone call was not returned, so I waited another couple of days and emailed the executive adviser with concerns that I was unable to get in contact with the operations manager. I received no response from any of these attempts at communication. I'm unsure what went wrong, as I was completely ghosted and apparently they decided not offer the job to me after all with no explanation. It's been several weeks since I last spoke with anyone.