Caterpillar Product Development interview questions

I applied online, 12 days later I was contacted for an interview. During this interview we just went through my resume. I was told that I should hear back about next steps in a week or so. A month and 3 days later I was contacted for another interview. It was a similar interview as the first one and I was told again that I should hear back within a week. 3 days later I was congratulated as I was moving to the next stage of interviews. I was asked for my availability, I gave them times that work for me. They then said they would talk with the team about the times and decide on one and will send out a calendar invite. I never received a calendar invite, and 16 days later I got a generic rejection email.