Why second staged dunning letter didn't generate?

Summary:

Content (please ensure you mask any confidential information):

We have defined Staged dunning configuration with Common set, checking the box for Include Current Invoices, not checking the box of Include Disputed invoices and Include Credit Memos and wait days for each letter as mentioned below:
Stage1→ Soft Letter→ 15

Stage2→ Medium Letter→ 1

Stage3→ Hard Letter→ 1

Stage4→ Final Letter→ 1

On 10/3 ran the required dunning programs and then Send Dunning Letter job, it generated a soft letter for the customer having the details of all the invoices which are due more than 15 days.

Question here: Is there a way to include all the due invoices in the letter which are due by equals or more than 1 day?