The solution is written in the same document, you are refering to.

"Note: After an update is performed, an update of the ACLs of all file systems should be
forced to take account of the new mappings.
"Check secmap mapping entries" on page 37 and "Update secmap mapping
entries" on page 38 describe these tasks."

Action
To update all the secmap mapping entries, use this command syntax:
$ server_cifssupport -secmap -update { -name
-domain | -sid }
where:
= name of the Data Mover
= name of the user or group
= the fully qualified domain name
= SID

Example:
To update all the secmap mapping entries on server_2, type:
$ server_cifssupport server_2 -secmap -update -user user3 -domain
NASDOCS
Output Note
server_2 : done The output displays all mappings that have
been updated.