Delete an Issue in Toolbox
To delete an Issue from your Project, go to the Issue Register and use the trashcan icon for the Issue you want to delete. If you don’t see a trashcan next to an Issue, then you do not have permission to delete it.
Note that Issues are numbered sequentially, so deleting Issues will leave gaps in the sequence.
It may be better to close the issue with a note explaining the reason the issue is not valid. e.g. a duplicate issue.
Only a Manager user can delete an Issue.