Thank you for your question!
Please note, by changing the payment term time will only take effect on transactions that happen after you have made the change, and not for transactions that you already have with open invoices. You can edit the payment term in your connectors, under configuration.
If you have a case (a transaction) where you would like to give the customer more time to pay his/her invoice, please contact our support so we can look at that specifically in detail. Our support team will happily help you under firstname.lastname@example.org.