Lti_consumer not returning grade - no error

I have been trying to integrate my site with an LTI provider. I am able to authorize and consume the provider but unable to receive a grade back from them. Is there any settings in nginx that would be required? I am using the xblock-lti-consumer. I am not receiving any errors on my server, only from the lti_provider.

I know this is not alot to go on, but thought I would see if anyone else has had similar issues receiving grades back from provider.

thanks in advance,