[CI] MixedClusterEsqlSpecIT test {stats.SumOfHalfFloat SYNC} failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #8730 / 8.13.4_bwc
• elasticsearch-periodic #8724 / 8.13.4_bwc
• elasticsearch-periodic #8718 / 8.13.4_bwc
• elasticsearch-periodic #8712 / 8.14.3_bwc
• elasticsearch-periodic #8712 / 8.11.4_bwc
• elasticsearch-periodic #8712 / 8.12.2_bwc
• elasticsearch-periodic #8706 / 8.13.4_bwc
• elasticsearch-periodic #8700 / 8.14.3_bwc
• elasticsearch-periodic #8700 / 8.11.4_bwc

Reproduction Line:

./gradlew ":x-pack:plugin:esql:qa:server:mixed-cluster:v8.13.4#javaRestTest" -Dtests.class="org.elasticsearch.xpack.esql.qa.mixed.MixedClusterEsqlSpecIT" -Dtests.method="test {math.AbsLong SYNC}" -Dtests.seed=ED1FDF4347E51D9F -Dtests.bwc=true -Dtests.locale=ka-Geor-GE -Dtests.timezone=Asia/Chita -Druntime.java=24

Applicable branches:
8.18

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: 
Data mismatch:
row 0 column 0:a list containing
row 0 column 0:0: expected "1" but was "null"
row 1 column 0:a list containing
row 1 column 0:0: expected "1" but was "null"
row 2 column 0:a list containing
row 2 column 0:0: expected "1" but was "null"
Actual:
l:long
null  
null  
null  

Expected:
l:long
1     
1     
1     

Issue Reasons:

• [8.18] 3 consecutive failures in step 8.13.4_bwc
• [8.18] 9 failures in test test {stats.SumOfHalfFloat SYNC} (11.8% fail rate in 76 executions)
• [8.18] 2 failures in step 8.11.4_bwc (33.3% fail rate in 6 executions)
• [8.18] 4 failures in step 8.13.4_bwc (66.7% fail rate in 6 executions)
• [8.18] 2 failures in step 8.14.3_bwc (40.0% fail rate in 5 executions)
• [8.18] 6 failures in pipeline elasticsearch-periodic (100.0% fail rate in 6 executions)

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

[elasticsearchmachine]

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