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New Issue view gives additional configuration that allows hiding fields from the Issue View page layout even if they are available on the Issue View screen (please note the difference between screen configured in Jira settings and page that you can see - they were the same in Old Issue View but New Issue View introduced "layout" concept which differentiates what you see from the screen configured).
Please go to Project settings > Issue layout page and move Checklist Content YAML and Checklist Text field to the Hidden fields column as presented on the screenshot:
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