Ensure that the "Ready for Prod" status is in the "In Progress" StatusCategory. This is a global Jira configuration under "Status".
If that is correct, then check if the affected issue(s) have a non-empty "Resolution" field. I believe an issue shows as "Done" (and the Key is shown in strikeout font sometimes) whenever the Resolution field has a value. If you find this commonly in a project, be sure to add a post-function to the workflow(s) which clears the "Resolution" field for transitions out of terminal states.
The Done with the check mark is the Resolution of the issue, and the green one is your Status. The resolution is used to indicate how the issue was closed. You can learn more about resolution and best practices here.