[CI] ClassificationIT testWithOnlyTrainingRowsAndTrainingPercentIsFifty_DependentVariableIsTextAndKeyword failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #6507 / openjdk17_checkpart4_java-matrix
• elasticsearch-periodic #6423 / openjdk17_checkpart4_java-fips-matrix

Reproduction Line:

./gradlew ":x-pack:plugin:ml:qa:native-multi-node-tests:javaRestTest" --tests "org.elasticsearch.xpack.ml.integration.ClassificationIT.testWithOnlyTrainingRowsAndTrainingPercentIsFifty_DependentVariableIsTextAndKeyword" -Dtests.seed=C0CEF00B809F7A0B -Dtests.locale=fr-GN -Dtests.timezone=Asia/Istanbul -Druntime.java=17

Applicable branches:
8.17

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: Stats were: {"id":"classification_training_percent_is_50_text_and_keyword","state":"started","progress":[{"phase":"reindexing","progress_percent":100},{"phase":"loading_data","progress_percent":100},{"phase":"feature_selection","progress_percent":100},{"phase":"coarse_parameter_search","progress_percent":89},{"phase":"fine_tuning_parameters","progress_percent":0},{"phase":"final_training","progress_percent":0},{"phase":"writing_results","progress_percent":0},{"phase":"inference","progress_percent":0}],"data_counts":{"training_docs_count":150,"test_docs_count":0,"skipped_docs_count":0},"memory_usage":{"timestamp":1739974487822,"peak_usage_bytes":19108,"status":"ok"},"node":{"id":"ICJOrzFMRCSIKyodcxFZ7A","name":"javaRestTest-1","ephemeral_id":"4APknY07RCiVVT1ysHLOKw","transport_address":"127.0.0.1:40773","attributes":{"xpack.installed":"true","transform.config_version":"10.0.0","ml.allocated_processors_double":"32.0","ml.machine_memory":"126604214272","ml.config
[truncated]

Issue Reasons:

• [8.17] 2 failures in test testWithOnlyTrainingRowsAndTrainingPercentIsFifty_DependentVariableIsTextAndKeyword (0.5% fail rate in 402 executions)
• [8.17] 2 failures in pipeline elasticsearch-periodic (15.4% fail rate in 13 executions)

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

[elasticsearchmachine]

Pinging @elastic/ml-core (Team:ML)