Hi Bob,
Based on the information, I would like to re-clarify the situation:
1. Did you mean that the user couldn't click the button on the second screenshot?
2. From the screenshot, I understand that the workflow is an Approval workflow. Is the user a member who is in the "Approvers" in the workflow configuration settings?
3. Could you provide a screenshot about the "Processing" situation when clicking "Submit" button in the InfoPath file for further research?
By default, only the users under Approvers in the workflow can have access to perform the task.
Best regards,
Jerry Cen