Does the subject want to ask, "What is the possible reason for the contact to reply to the unscheduled interview afterwards?" Wait for the resumes of other candidates for further screening.

1. The HR department is waiting for the resumes of other candidates, or waiting for the internal approval process to be completed. It took some time, so I didn't arrange an interview right away.

2. The personnel department is interested in the resume, but it needs further evaluation and screening to determine the suitable candidate for the interview.