As a layman, my understanding is that soap (or other residue) builds up due to low temperature washing. High temperature washes break down the build up.
I believe most front loaders these days have both a self clean cycle (you're supposed to run it every month or two, it's basically an extremely long hot water rinse+spin that you don't add soap or put clothes in for), and a drain filter that should be accessible near the bottom front (expect black slime if you haven't cleaned the filter recently).
I believe most front loaders these days have both a self clean cycle (you're supposed to run it every month or two, it's basically an extremely long hot water rinse+spin that you don't add soap or put clothes in for), and a drain filter that should be accessible near the bottom front (expect black slime if you haven't cleaned the filter recently).
https://youtu.be/-v4QQcceoH0?si=yOqC6Wd9HPxQo5U9