Apache Druid Appending Segment without dropping or summing it

I have three JSON files with the same timestamp but different values to upload to the Druid. I want to upload them separately with the same segment granularity. However, it drops the existing segment and uploads the new one.

This is a companion discussion topic for the original entry at https://stackoverflow.com/questions/71783263/apache-druid-appending-segment-without-dropping-or-summing-it