The mortgage payments on my primary home and on my rental both decrease by 3% year after year, but my mortgage is fixed, so the total payment doesn't change.

Why is the system reducing my payment like this? It doesn't show a principal/interest breakdown, which could make sense if it had asked me for my rate and was showing the interest only portion, but the first year's payment is both principal and interest.

Is it inflation? I have inflation set at the default 3% per year, but it seems that none of the other numbers are affected by inflation in this way. Our labor income increases by the 2% I set it at (not the 1% net it would show if inflation is included) for example.

Pardon me if this is stuff everyone knows. I'm new to ESPlanner. Thanks!