Why does Header Content-Type for POST request differ between chrome and firefox only in by "UTF-8" vs "utf-8"?
Either force both sides to uppercase or lowercase to guarantee a match no matter which browser sends it in.
Not sure which function it is so you may have to look it up, but this is good enough to make my point.
if lowercase(request.headers['Content-Type']) in ['application/json;charset=utf-8']: