Customer Payment Method Qualifier not applied on order

Dears,

We are trying to create a modifier with a line qualifier stating that if a customer have a "Payment Method" equals to "Cash", then the order should have this modifier applied.

Even though the customer has the payment method equal to "Cash" (on account level and on site level), the modifier is not being applied.

Can you please advise what should be done to solve this issue and to have the modifier applied when he is qualified ?

Thank you,

Regards,