Users unable to newgrp to secondary group from NIS master

Issue

• I have a group 'users' that i've added it to a NIS group file as the secondary group for some users.
• Although I tried to newgrp into the group 'users' with one of the users, it just came back with "Sorry" and does not change the group.

> newgrp users
Sorry.

• /etc/nsswitch.conf has the following information

passwd:     files nis
shadow:     files nis
group:      files nis

• The group 'users' is not present in the /etc/group file on the NIS Client.
• "ypcat group" command can return the group information correctly including all members.