Zoho Books integration with Zoho Creator - Issue with contact person ("contact_persons" - create invoice)

Zoho Books integration with Zoho Creator - Issue with contact person ("contact_persons" - create invoice)

Hello,

I was wondering if somebody could help:

I have managed to create invoices on Zoho Books using zoho.books.createRecord() Deluge task, except for the API field "contact_persons" which generate the following error:


Return Value: 
{code=1002, message=Contact Person does not exist.}

This does not make sense since I have passed the contact person ID as map value (which I have fetched from zoho books)
It's  annoying as it's so far the only field that is causing trouble & I would need to send the invoice by email using integration task 

Can I pass a different value? 
Could it be the field "contact_persons" which has changed?

Sample from the code

response = zoho.books.createRecord("invoices","*********",{"customer_id": "1***70000013*****","contact_persons": ["16***700000******00"], ...

Many thanks in advance for your advice,

Claire