This article provides guidelines on how to verify verifying why a field is NOT being copied when cloned.
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If you find yourself in a situation where a certain particular field is not being copied, ask yourself 2 two questions:
Is the field included in the exclude fields list?
If the answer to this is YES, remove the field from the exclude fields list.
A field on the exclude fields list will not be updated and will be empty/cleared on the cloned issue.Is the field in context and on the screen?
A If a field is not on the screen, that field value cannot be updated if it is not on screen.
If the field is not appearing on the screen, you need to add it. Follow this article for that: https://support.atlassian.com/jira-cloud-administration/docs/add-a-custom-field-to-a-screen/
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