You probably know this but "Yes" is true, and "No" is false, so if you're patching to the list you need to use the true/false values.
Definitely need more information though:-
1. What control is being used in the app? Toggle/Checkbox etc...
2. Default of the Sharepoint Column is it Yes or No?
3. Are you using a form to submit back to the list? Is the Submit button using the SubmitForm() function.
4. Does the item actually write to the list and then dissappear? or does it just dissappear from the form?