Overview:
The minor versions of a document are not deleted after passing through a workflow that includes a state with the entry action Delete Minor Versions.
Root Cause:
Check the order of the workflow actions.
If a state change occurs prior to a Delete Minor Versions action to Set New Major Version, it does not delete the minor versions of the document.
Solution:
Include both entry actions, Set New Major Version and Delete Minor Versions, in the same state in order for the minor versions to be deleted as expected.
Related Documentation:
Vault Help Documentation: Defining Document State Entry Actions