Opportunities that show up in the Compose stage of the Workflow saying 'Compose #2' or 'Compose #3' are appearing due to the auto follow-up sequence not being enabled during the initial outreach. The system has recognized that you sent out your first (or 2nd email) and have not received a reply. Now, enough days have passed between emails and it is time to follow up!
To enable the auto follow-up sequence for an opportunity, check the boxes next to the opportunity with the follow up due and select ‘Launch Automation Sequence’. This will also continue the auto follow-up sequence for future contacts.