I must have been editing /etc/shadow to add myself to the group, neglecting to modify /etc/gshadow. When using gpasswd to add myself to the group, which modifies both files, newgrp <group> works as expected.
I must have been editing /etc/shadow to add myself to the group, neglecting to
modify /etc/gshadow.
When using gpasswd to add myself to the group, which modifies both files, newgrp
<group> works as expected.