Fix isolated margin ntli encoding

[boyi]

Pull Request

Description

Brief description of the changes in this PR.

Type of Change

• [*] Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring
• Performance improvement

Testing

• [ *] I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have run make test and all checks pass

Code Quality

• [* ] My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

Generated Code

• [* ] I have run make generate and committed any generated files
• Generated files are up to date with struct changes

Breaking Changes

If this is a breaking change, please describe the impact and migration path for existing users:

Screenshots (if applicable)

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Additional Notes

Any additional information that would be helpful for reviewers.

[sonirico]

why is this needed?

[boyi]

Not sure if it would change the default behavior.

[sonirico]

we have to be sure about changes submitted in PRs, right?