Workflows; Version 2; Publishing Documents Immediately not always working as expected

When a Version 2 Document type Workflow Item (e.g., an SMS) is configured to 'Publish Immediately', this was not always happening, e.g., if a non-automatic Workflow Item was configured to send an SMS Document and the User actioned the Item from the Workflows form, the SMS would not be sent immediately; the Log's Publish Status would still be 'To Send'.