I am getting some strange behavior from the header field on the front-end. The code is rather complicated so I made a brief (3 minute) video to demonstrate the issue.
The metabox code itself is standard and works well when the header field is not included. But, when the header field is included, it closes the form just after the header field and leaves the front-end display looking bad.
I've just checked the heading field and it's all fine. Can you take a screenshot of the console before the closing </form> tag, so we can see which field closes the div incorrectly?
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