A. The universal syslog forwarder is stripping these fields before sending the logs to XSIAM. Inspect the forwarder's configuration and output.

B. The XSIAM parsing rule's regex patterns for 'user_id' and 'action_type' are incorrect or too restrictive, failing to extract the values from the raw log format. Utilize the XSIAM Parsing Rule Editor's 'Test Parser' functionality with sample logs.

C. The data schema defined in XSIAM for this data source does not include 'user_id' and 'action_type' as fields, leading to their discard during normalization. Check the data source schema definition.

D. The log's character encoding is not supported by XSIAM, causing parsing errors for specific characters within those fields. Verify the log's encoding and XSIAM's configured encoding for the source.

E. The XSIAM tenant has reached its daily data ingestion quota, causing partial log processing. Review XSIAM license and usage metrics.