Cookie issue for Jupyterhub with reverse proxy

I am currently trying to host jupyerhub in docker and using our custom reverse proxy build with core on top of it. Currently we are using dummy authenticator just for testing. The login is working fine, but it cannot spawn the server and in back end I am getting following error.

16:39:19.732 - debug: [ConfigProxy] PROXY WEB /gateway/acrconnect-jupyterhub/hub/spawn to http://jupyterhub:8080
[W 2020-05-22 16:39:19.735 JupyterHub base:392] Invalid or expired cookie token

It is saying cookie is invalid or expired. I am not sure why Jupyter cannot read the cookie.