[CI] XPackRestIT test {p0=esql/10_basic/basic with documents_found} failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #9183 / single-processor-node-tests
• elasticsearch-periodic-platform-support #9189 / almalinux-8_platform-support-unix
• elasticsearch-periodic-platform-support #9175 / almalinux-8_platform-support-unix
• elasticsearch-periodic-platform-support #9154 / windows-2025_checkpart3_platform-support-windows
• elasticsearch-periodic #9105 / openjdk17_checkpart3_java-matrix
• elasticsearch-intake #24877 / part3
• elasticsearch-periodic #9077 / openjdk23_checkpart3_java-matrix
• elasticsearch-periodic-platform-support #9077 / amazonlinux-2023_platform-support-aws
• elasticsearch-periodic-platform-support #9062 / oraclelinux-9_platform-support-unix

Reproduction Line:

./gradlew ":x-pack:plugin:yamlRestTest" --tests "org.elasticsearch.xpack.test.rest.XPackRestIT.test {p0=esql/10_basic/basic with documents_found}" -Dtests.seed=99AD545FAF01E145 -Dtests.configure_test_clusters_with_one_processor=true -Dtests.locale=vec-Latn-IT -Dtests.timezone=America/Ojinaga -Druntime.java=24

Applicable branches:
8.19

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: Failure at [esql/10_basic:200]: 
Expected: <10>
     but: was <9>

Issue Reasons:

• [8.19] 9 failures in test test {p0=esql/10_basic/basic with documents_found} (1.2% fail rate in 722 executions)
• [8.19] 2 failures in step almalinux-8_platform-support-unix (11.8% fail rate in 17 executions)
• [8.19] 3 failures in pipeline elasticsearch-periodic (15.0% fail rate in 20 executions)
• [8.19] 5 failures in pipeline elasticsearch-periodic-platform-support (25.0% fail rate in 20 executions)

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

[elasticsearchmachine]

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

[elasticsearchmachine]

This has been muted on branch main

Mute Reasons:

• [main] 6 failures in test test {p0=esql/10_basic/basic with documents_found} (1.0% fail rate in 624 executions)
• [main] 5 failures in step rest-compatibility (3.2% fail rate in 158 executions)
• [main] 5 failures in pipeline elasticsearch-pull-request (3.1% fail rate in 162 executions)

Build Scans:

• elasticsearch-periodic #9022 / openjdk24_checkrestcompat_java-matrix
• elasticsearch-pull-request #78052 / rest-compatibility
• elasticsearch-pull-request #78025 / rest-compatibility
• elasticsearch-pull-request #77972 / rest-compatibility
• elasticsearch-pull-request #77790 / rest-compatibility
• elasticsearch-pull-request #77778 / rest-compatibility

[elasticsearchmachine]

Pinging @elastic/es-analytical-engine (Team:Analytics)

[elasticsearchmachine]

Pinging @elastic/search-eng (Team:SearchOrg)

[elasticsearchmachine]

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