Is it possible for refi rate to change after lock?

[Patrick Orah]

I am in the process of refinancing my loan and as most have experienced it is taken a very long time to close. I am towards the end of closing after what seems like forever working with my lender and when they sent me the closing disclosure I noticed that my interest rate went from 3.125% to 3.375% and $3k in financing fees to buy the rate down to 3.375%. The issue that I have is that I locked my rate at 3.125% and now the terms have changed. I suspected that the lender or loan officer made a mistake and did not lock my rate and is now giving me all kinds of excuses, one being that the appraisal came back $30k less than expected which changed the terms of the rate. Is that possible? Can my rate change to a higher rate after I have locked in at a specific rate?