Invoice Date and Due Date has been changed after update invoice via api

Invoice Date and Due Date has been changed after update invoice via api

Trying to update invoices via API. I send this json:
  1. {
    1. "invoice_id": "11111",
    2. "invoice_number": "#11111",
    3. "reason": "Updated via API",
    4. "line_items": [...]
  2. }
Zoho updates invoice successfully, but Date and Due Date changed. 
For example i have Date = "2022-05-02" and Due Date = "2022-05-17", but after update new values were:
Date = "2022-05-17" and Due Date = "2022-06-01".
I don`t know is this important, but payment terms: "Net 15"