Why doesn't the 'New Submission' button appear for authors after account creation?

I set up the Account Creation Form for authors to create their accounts so they can access the abstract submission form. However, after creating an account, authors can see the 'My Submissions' page but do not see the green 'New Submission' button to submit abstracts.

The 'New Submission' button may not appear if the setting 'Late Breaking Submissions? Select roles who are allowed to submit late breaking submissions:' is enabled and limited to specific roles under your Submission Settings. 

This option restricts abstract submission access based on roles, typically used after the submission deadline. To allow all authors to submit abstracts, disable this setting or ensure it includes all relevant roles. 

Disabling the late-breaking submissions role restriction is usually the simplest fix to make the 'New Submission' button appear for all authors upon account creation.