Dunning letters goes to secondary email id

Dear Members,

Can some one help me on this please.

Dunning letters are going to secondary contact email id even though customer has primary contact role in active mode.

Let say we have two contact A & B, while A is primary contact, B is the secondary contact . Both, contacts are having the dunning roles defined.

My assumption is, the dunning should be sent to contact A which is Primary contact having the dunning role assigned but system is sending the dunning to secondary contact.

Please review the screens attached.

I've already raised the SR(XXXXXXXXXXX) which in progress but not found the root cause so far