[CI] MixedClusterClientYamlTestSuiteIT test {p0=search.vectors/42_knn_search_bbq_flat/Vector rescoring has same scoring as exact search for kNN section} failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #7461 / openjdk23_9.0.0_java-matrix-bwc
• elasticsearch-pull-request #65989 / 9.0.0_bwc-snapshots
• elasticsearch-pull-request #65989 / 8.19.0_bwc-snapshots

Reproduction Line:

./gradlew ":qa:mixed-cluster:v9.0.0#mixedClusterTest" -Dtests.class="org.elasticsearch.backwards.MixedClusterClientYamlTestSuiteIT" -Dtests.method="test {p0=search.vectors/42_knn_search_bbq_flat/Vector rescoring has same scoring as exact search for kNN section}" -Dtests.seed=8EA4B61C9E959D2D -Dtests.bwc=true -Dtests.locale=rof -Dtests.timezone=Europe/Chisinau -Druntime.java=23

Applicable branches:
main

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: Failure at [search.vectors/42_knn_search_bbq_flat:142]: 
Expected: <3>
     but: was <2>

Issue Reasons:

• [main] 3 failures in test test {p0=search.vectors/42_knn_search_bbq_flat/Vector rescoring has same scoring as exact search for kNN section} (0.4% fail rate in 754 executions)

Note:
This issue was created using new test triage automation. Please report issues or feedback to es-delivery.

[elasticsearchmachine]

This has been muted on branch main

Mute Reasons:

• [main] 3 failures in test test {p0=search.vectors/42_knn_search_bbq_flat/Vector rescoring has same scoring as exact search for kNN section} (0.4% fail rate in 754 executions)

Build Scans:

• elasticsearch-periodic #7461 / openjdk23_9.0.0_java-matrix-bwc
• elasticsearch-pull-request #65989 / 9.0.0_bwc-snapshots
• elasticsearch-pull-request #65989 / 8.19.0_bwc-snapshots

[elasticsearchmachine]

Pinging @elastic/es-delivery (Team:Delivery)

[elasticsearchmachine]

Pinging @elastic/es-search-relevance (Team:Search Relevance)