[BUG] Hybrid Search results are missing when concurrent search is enabled

[vibrantvarun]

What is the bug?

Hybrid search results are missing when concurrent search is enabled in single shard and multiple shards scenario.
For example:
For single shard I ingested 6 documents and did a matchAll query under the hybrid clause then I am expecting 6 results should be there but I am getting just 5 results.

For multiple shard I did the same by ingesting 100 documents and I am expecting 100 results but getting 95.

How can one reproduce the bug?

1. Just ingest the documents for single shard by following URL http://localhost:9200/my-nlp-index/_doc/1?refresh=true and make sure update docId when ingesting new documents.
2. Enable the concurrent search in index settings
3. For multiple shard use code to ingest 100 documents in a same way
4. Do a match all query with maximum results size, you will find the results are missing.

What is the expected behavior?

Results should not be missing and the right of results should be returned.

Do you have any additional context?

When concurrent search is disabled everything is working fine.

[vibrantvarun]

@martin-gaievski assigning this to you

[vibrantvarun]

@martin-gaievski Can we close the bug?

[martin-gaievski]

yup