Not necessarily a complete answer, but I think some browsers don't accept multiple entries in the "Access-Control-Allow-Origin" header. I don't know if Firefox is one of them.
I had an issue with my server. When I tried the same code on different server, it worked! I was using shared hosting , where it was disabled by the service provider.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.