Hi Ivan Akira!
I think - for Indonesian language is the "new" ‘id’ - Indonesian (formerly in) used.
Means all Pages in Indonesian language have a category "id:" and the ENGLISH Page names.
And : all include:language… pages have to be controlled to include the id: category too.
Hope this helps for the start?
and of course: the nav:side page: nav:side-id - which is on the start only a litle copy of the english one…