Mortgage Question - Rate Lock

[Valessa Davis]

Currently under contract for an investment property with a rate lock in place and agreed 15% down payment due to great credit scores. During the due diligence I negotiated the price down $15k. Now the lender says they cannot honor the rate lock because they have certain set cost that have to be paid and with the purchase price now $15k lower they would be losing money. They are raising the rate a whole point higher and now requiring me to bring 25% for the down payment. Does a lender have to honor the initial rate lock and agreed 15% down payment even if they have to take a loss?