[CI] IndexStatsIT testFilterCacheStats failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #6887 / openjdk21_checkpart1_java-fips-matrix
• elasticsearch-pull-request #60929 / part-1

Reproduction Line:

./gradlew ":server:internalClusterTest" --tests "org.elasticsearch.indices.stats.IndexStatsIT.testFilterCacheStats" -Dtests.seed=6D428E2B759773A9 -Dtests.locale=lkt-Latn-US -Dtests.timezone=America/Mexico_City -Druntime.java=21 -Dtests.fips.enabled=true

Applicable branches:
main

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: 
Expected: <1L>
     but: was <-1L>

Issue Reasons:

• [main] 2 failures in test testFilterCacheStats (0.4% fail rate in 506 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] 2 failures in test testFilterCacheStats (0.4% fail rate in 506 executions)

Build Scans:

• elasticsearch-periodic #6887 / openjdk21_checkpart1_java-fips-matrix
• elasticsearch-pull-request #60929 / part-1

[elasticsearchmachine]

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

[elasticsearchmachine]

Pinging @elastic/es-search-foundations (Team:Search Foundations)