This is working for me, defined the priv and mapped to a role using both the pl/sql API and the SQL Developer REST Development screens
l_roles(1) := 'SQL Developer';
p_privilege_name => 'hyph',
p_roles => l_roles,
p_patterns => l_patterns,
p_modules => l_modules,
p_label => '',
p_description => '',
p_comments => NULL);
It worked. But I am afraid there is some kind of bug in Application Express? Trying to perform the same operation, could not be done.
I am using Application Express 19.1.0.00.15
It appears so, so I would post a note in their space.