Passing multi-line text field content to api, not JSON safe

Hi - I'm using a multi-line TextField to display simple text, and allow the user to update it, but I found that when the user adds a new line in the TextField box, I get errors when passing that field content to an api call to update the record.

I believe the issue is that the field is no longer JSON safe, since new lines in the input aren't JSON safe.

Is there a setting for the TextField widget to ensure its contents are JSON-safe, or another widget I should be using for multi-line content saved as type String?

(Field in question is the Description field in the screenshot)