A. The application update changed the timestamp format, and the XSIAM parsing rule's 'time_format' or 'time_field' setting is no longer correctly configured to extract and parse 'eventTime' as the primary timestamp for the event. The XSIAM parsing rule needs to explicitly set 'time_field: eventTime' and specify the correct 'time_format: IS08601 or a suitable 'strptime' pattern.

B. The XSIAM Collector's internal clock is out of sync with the application server. Synchronize the NTP on the Collector. This would affect all logs, not just specific ones.

C. The 'eventTime' field is being dropped during normalization because it's not mapped to a standard CIM field. This doesn't explain '_time' defaulting to ingestion time.

D. The XSIAM Data Lake is experiencing high latency, causing delays in '_time' field indexing. This affects query performance, not the source of the '_time' value.

E. The XSIAM license has expired, leading to partial data processing and timestamp issues. This would cause broader ingestion failures, not specific timestamp re-writes.