ProductPlan lets you synchronize multiple fields for Bars and Containers with Jira. You can synchronize Title, Description, and/or Percent Complete. Syncing will automatically once each day, or you can manually sync any time.
To enable syncing, go to the Integrations page and enable the fields you want to sync. Syncing will update the field in ProductPlan with the data in Jira. There is no way to undo this. If enabled, all existing bars with a single Jira link will have their Title and/or Description replaced with the one from Jira.
If you do not want to sync the Title or Description for an individual Bar or Container you can prevent this by going to the Details screen of the Bar and clicking the link next to the field and unlinking it.
You can read more about how Percent Complete is calculated here.