Below are some of the most common reasons
- Only HP QC version 11.5 and above are supported to sync the test steps.
- Configurations are not defined in ConnectAll for Zephyr for JIRA issue type and Test Steps field
- Make sure the field mapping is defined, for "Steps" > "Zephyr Test Step"
- Make sure to have Step Name, Step Result fields have values. A test step cannot be synced without these values in the test steps.