question

I am building a smart home skill for a basic outlet device.
For start i used Login with amazon and everything seemed to be working fine.
I then replaced account linking with my own oauth server.
Alexa hits auth page of my oauth server and is redirected back to a valid redirect uri with code.
But, after that aelxa never hits token endpoint and message is displayed - "We were unable to link skill at this time."

My oauth server is hosted over SSL and using certificates from one of the approved authorities.