Changing queue_id for the same build

Starting the jenkins build with jenkins api via post request
${jenkins_url}/job/Sleep3/build
Then I start more builds. And I noticed strange behaviour - new build with id, for example, 100, at first placed to the queue with id 100. Than it removed from queue and then again placed to queue with id 101. Why this is happening?

queue ID is a global incrementor. It always goes up until it resets on Jenkins restart.

Searching post history you can learn more about it Question on Jenkins reuse same queue_id