Different Elasticsearch results for the same query

Question

I\'ve setup Elasticsearch with 1 cluster á 4 nodes. Number of shards per index: 1; Number of replicas per index: 3

When I call a simple query like the following one

Answer 1

This question helped me, as the answer says,

One of the possible reasons could be distributed IDF, by default Elastic uses local IDF on each shard, to save some performance which will lead to different idfs across the cluster.

ES doc here