Dev environment LTI deeplink submit shows login page

[TomDoesb]

Summary:

I've got the canvas docker image running with SSL on my local dev environment. I've got my LTI configured and the LTI authentication is working fine. However when I try to create a deeplink canvas shows the login screen when the final post is sent. I imagined this being a secure cookie issue and i copied the session_store.yml.example to a session_store.yml and uncommented the secure: true lines and re-deployed.

Expected behavior:

The deeplink is posted succesfully and added to the course module

Actual behavior:

The login page is shown