Since Xray {version} there are restrictions when linking Xray issues with Xray links. This does not affect Jira Issue links.

• Tests can only be added to Test Plans/Test Sets/Test Executions which are editable by the current user.
• Test Executions can only be added to Test Plans which are editable by the current user.
• Pre-Conditions can only be added to Tests which are editable by the current user.

For example, it is not possible to add a Test to a Test Plan that is closed.