IQVIA Consultant interview questions

The interview process seemed to be moving fine until HR informed me that the Hiring Manager has requested an onsite interview. I was excited about the prospect of interviewing onsite and provided my availability to them. That is the last I heard from HR. Despite multiple attempts to contact her through phone, email, I did not get any response and did not understand why the process ended so abruptly despite getting a green signal for an onsite final round. If they had changed their mind regarding my candidacy, I would have appreciated an email saying they found someone better. This was very unprofessional and this experience has left a bad taste in my mouth.