Limited number of users with the same name appeared in the page restriction search

Only 6 of user return in the search result of page restriction but none of them is the intended user. Not able to add the intended user to page restriction

STEPS TO REPRODUCE

1. Add user with username test, test1, test2, test3, test4, test5, test6, test7
2. All the username must have the same Full Name: Test

EXPECTED BEHAVIOR

Able to search and identify the user in the search result for page restriction

ACTUAL BEHAVIOR

Search for the 'test' user but could not identify the exact user and none of them is the intended user and it hard to identify the user

WORKAROUND

1. Temporary change the full name of the affected user to a unique name. But this could prove troublesome for the user that belongs to external directories.
2. Assign the affected user to a group and apply the page restriction to the group instead. This workaround will add another extra management to the new group