An issue was added to the structure. Afterwards, the issue was moved in JIRA to another project. Now, the issue cannot be found in the structure, either by summary, or by the new or old issue key. What happened?
Please check that the project where the issue was moved to is enabled for Structure. Structure plugin ignores issues in the projects that are not Structure-enabled, so the moved issue is ignored too, as if it ceased to exist.
If you need this issue in the structure, either include the project where the issue resides now into the list of Structure-enabled projects or move the issue to an already Structure-enabled project, e.g., to the original project.