Users info missing in result of system catalog system.completed_requests

We are using MDS architecture based Couchbase cluster and the issue which we have noticed recently is: We couldnt find users info in the result of few system:completed_requests query. The Query Monitoring also shows blank in users column for those queries.

Please let us know the rootcause of this issue.

These will be shown in CB 5.0 and above. cc @marcoeg

           "userAgent": "Go-http-client/1.1 (CBQ/2.0)",
            "users": "Administrator,Administrator"

Are you running mixed version nodes?
Could you provide complete node version information?
As @vsr1 is saying, user information should appear in 5.0.