Character waiver shouldn't be necessary unless your document IS fake. If it is erroneous (and they often are out of particular markets where over-population is ahead of the countries technological ability to have robust and accurate centralised birth records) , that is different.
You should wait for the case officer to come back to you after discussing it with his or her T/A. If there is legitimate reason to hold suspicions about the authenticity of your document they are obliged to follow a 2 step process:
1. put the concerns to you, and ask for your clarification, and
2. if your answer confirms it is a fake or forgery, then they will require you to give a formal response - in favour of a character waiver.
You need to consult a lawyer, as soon as they commence #1.
Good luck.