If a client is being charged twice as much as expected, it may be because they are currently set up with double the number of products.
The payment module contains a list of subscriptions. However, this list only reflects active subscriptions—it does not represent the full list of products associated with the client.
When using Multiple Payments as the payment method for a client, multiple invoices are scheduled right from the start.
These planned invoices will immediately appear in the invoice list, as shown in the image. If an invoice is in the PLANNED state, it was generated through the Multiple Payments setup.
While an invoice remains PLANNED, it can still be edited or deleted.
With Multiple Payments, no additional invoices will be generated beyond the ones already planned. So, if all planned invoices are deleted (by right clicking), only future invoices from subscription products will be generated.