Locked Interest rate changing during closing?

[Chase Caudill]

Hello I close on a a four unit in two weeks. I locked my interest rate and I understand you normally can't get out of that rate. However I'm just trying to see if there are any stipulations to get out of that locked rate? My appraisal came back low and the loan amount and down payment are now changing because of this. I'm hoping this can allow me to change my rate and snag a lower interest rate.Not sure if this is possible or not, but I can't find information on it anywhere.