A customer note can be added to an invoice by editing the invoice.

When a NEW invoice is created via a subscription (i.e. renewal etc) , the customer note previously added to a different invoice, appears on the NEW invoice.

It acts as though it is the default entry now.

It would be beneficial to add a feature where I could toggle whether I want an entry to be a default or do I want to have this entry for this invoice alone. 

In other words, I want each NEW invoice customer note to be blank.