Issue Summary

When a user is trying to log in to an instance for the first time using a URL that doesn't point toward a specific target results in a generic frontend error, stating that "Something went wrong".

Steps to Reproduce

1. Invite a new user to your instance.
2. Let the user try to log in using (just an example) the below URL (replace the <your-instance> part as well as the project key.

https://<your-instance>.atlassian.net/jira/software/c/projects/TEST/list?direction=ASC&sortBy=status 

Expected Results

The user, even not having access to the (example) TEST project, should be able to log in and see an error they don't have permission to view the project or its issues.

Actual Results

Looking at the developer tools (network tab), the respective call to the below endpoint throws a generic HTTP 400 error with the message "Session token is missing in payload.".

https://<your-instance>.atlassian.net/gateway/api/session/heartbeat 

{
    "key": "Bad Request",
    "context": {
        "message": "Session token is missing in payload."
    }
}

Workaround

Let the user log in (only for the first time) via one of the below URLs instead.

https://<your-instance>.atlassian.net/jira/your-work

https://<your-instance>.atlassian.net/welcome/software