If the Automation with setting checklist does not work, please start with testing the Checklist Template field manually:
Add Checklist Template field to the issue Edit/View screen
Manually select/set value in the Checklist Template field on the issue page
Wait for a couple of seconds (so Jira has time to notify the Issue Checklist server that the template was set through the Checklist Template field)
Refresh the issue page and see if the checklist items (with clickable checkboxes) were added successfully (and the Checklist Template field has been cleared at the same time)
Manual selection of the Checklist Template field value succeeds
If the above works correctly and you can see the checklist items, it means that the process works fine overall, but there is something wrong with your Automation rule. Maybe you picked an incorrect ID for the checklist template option? You might inspect the issue History tab to see if Automation did work and set value for the Checklist Template field.
You can also inspect the Automation log if the rule failed and see what the reason was.
Manual selection of the Checklist Template field value fails
If the above bullet point procedure does not work, then please check if the list of checklist templates as you can see them on the templates page/dialog is exactly the same as in the Checklist Template dropdown field.
Checklist Template field is not synced with the list of templates
If the list is different, please do the following:
Find all issues with the non-empty Checklist Template field. Here is the JQL: "Checklist Template" is not empty”
Clear Checklist Template field for those issues (if there are many of them, use the “Bulk Update” option)
Find all issues with the non-empty Checklist Template field again and validate that the search result is empty
Add or edit any template to trigger re-sync between the list of templates and the Checklist Template field
Validate again that the Checklist Template field contains exactly the same list of templates as you can see on the templates page/dialog.
Try the first bullet point procedure again to see if picking value in Checklist Template dropdown adds checklist items/checkboxes to the issue
Checklist Template field is synced with the list of templates
In that case, if the manual selection of the value in Checklist Template dropdown still does not apply the template to the issue, please try the following:
Reload the page after a couple of minutes to validate if the template was loaded.
Jira is sometimes late letting Issue Checklist know about changes in the issue. Also, the communication between Jira happens in the background (outside of the browser) so page reload is required to see the changes in the checklist related to issue update action. If it doesn’t help, please proceed below.
Uninstall and install again Issue Checklist app (all data stays safe during that time as we hold it for some time after uninstall as per our Privacy Policy).
Reinstalling the app will store the proper Jira Checklist Template field ID in the database. Incorrect ID can be a cause of non-working integration between the Checklist Template field in Jira and Issue Checklist templates.