I have done some research on Indonesian citizenship laws and while yes, he might have had dual citizenship until age 18, it did not extend into adulthood unless he actively chose that citizenship over US.
I just posted in this thread my thoughts on the ‘non release’ of the bc. Should just be up a couple of posts.
You have to chose your citizenship at age 18. There is no indication that he ever did this. And there must be something on the birth certificate, or he wouldn’t be hiding it.