Dear Customer,
Please follow the below KB article to resolve the issue.
Use of data enrichment can prevent source user and destination user from being parsed in Windows events
Technical Articles ID: KB88982
https://kc.mcafee.com/corporate/index?page=content&id=KB88982
Please check the below KB article as well if the above KB article does not resolve your issue:
Some events are not showing the Source User field in the Details tab
Technical Articles ID: KB82114
Last Modified: 4/23/2020
https://kc.mcafee.com/corporate/index?page=content&id=KB82114&actp=null&viewlocale=en_US&locale=en_U...
Regards,
Prashanth B Pillai
McAfee Technical Support
Customer Success Group