What should we do if the interviewer doesn't come for an interview at the appointed interview time and calls to ask why, and the other party says the interview is in another unit?

Modern recruitment is a two-way choice, as employers often say, please go back and wait for our reply, but it is often useless to reply. When the applicant calls to ask, the employer will say sorry. We think others are more suitable for this position. Thank you for your attention.

Therefore, as an employer, there is nothing special to communicate with the other party, even if you say response.

If the other person is delayed in the last interview unit because of traffic and time, he will naturally explain to you and propose another time. You should give some understanding and reschedule according to the time situation.

If the other person simply wants to contact another company first and communicate well, he will not ask you out again, which is naturally regarded as giving up the interview. This is a very normal thing. I don't think you will wait for such an interviewer.