The only way that a fixed-rate loan could have a lower monthly payment is if there were a balloon payment at the end, or if the monthly payments increased over time, both of which should be very clearly indicated at some point.

I originally thought that the "fees" could include points that would lower the rate, but that payment would equate to a roughly 0% rate (1831 * 15 * 12 = 329,580), and those fees aren't nearly high enough to lower the rate 2.5%.

Personally I'd assume it's just using a different loan amount (that payment gives a PV of $274,600).

The only way that a fixed-rate loan could have a lower monthly payment is if there were a balloon payment at the end, or if the monthly payments increased over time, both of which should be very unusual and would need to be clearly indicated early in the process.

I originally thought that the "fees" could include points that would lower the rate, but that payment would equate to a roughly 0% rate (1831 * 15 * 12 = 329,580), and those fees aren't nearly high enough to lower the rate 2.5%.

Personally I'd assume it's just using a different loan amount (that payment gives a PV of $274,600).