Veeva Systems Senior Program Manager interview questions

Went through multiple rounds of interviews for the Quality Systems team (5-6 rounds with a job skills assessment). Received a verbal offer with comp details after reference checks, then they stalled on the paperwork for 3 weeks while apologizing and saying it would be sent soon. Then without an explanation they rescinded the offer and refused to provide context but said they were going in a different direction. my assumption is that they stalled while waiting for another candidate or internal hire, but i have no way of knowing.