Cannot grant privilege for translating glossary

I'm a translation maintainer. When I try to manage permissions of project members, I can only grant 'Translate Content' and 'Review'. Strange thing is I can also put a check mark on 'Translate glossary', but after I save permissions, it doesn't apply as it is. Their roles are also shown as 'Korean Translator, Reviewer', not including 'Glossary translator'.
Because of this problem my project is having difficulty in using project glossary. plz check what is wrong with it.