If a property located in zone A is grandfathered as zone X, does the bank still have the responsibility to ensure flood ins in maintained for the life of the ln? Doesn't the borrower have to have flood ins, they just get it at a reduced rate?

Yes and yes.

Thank you...these lenders are so stubborn! They would argue with a post.

Because the property is grandfathered does not change the fact it is now located in a SFHA. The grandfathering just allows the property owner to purchase flood insurance at preferred rates.