We generally use index refresh in ITs (running ES in Docker) and it fails occasionally, which I believe the case described here: "The (near) real-time capabilities depend on the index engine used." https://www.elastic.co/guide/en/elasticsearch/reference/curr...
That seems to be the issue then. The refresh flag should be passed in your insert/update/delete operations.
The refresh command can also be called (which is what you're doing) but this is a different operation and just triggers the index build with no guarantees that it finishes or is consistent with any particular data mutation.
Did you read the previously posted documentation for the refresh flag?
