I think we need more information about how you use the machine.

• how often do you wash?
• do you use long or short cycles and hot, warm, or cold?
• what products do you wash with?

My front loader stank when I did two loads a week on the same day. Both cold. Both using an inexpensive detergent. If I didn’t get the washing out of the machine right away it would need a rewash because of the smell.

When I had a kid and started using cloth diapers that changed. I started washing in hot water, washing every second day, I used good quality detergent (and controversially a lot of it). I still don’t wash everything on hot and I don’t use as much detergent for my clothes as I do for poop smeared diapers, but my machine never smells anymore. More amazingly I can leave the washing in the machine over night, or two nights (which can happen when the laundry isn’t inside the main house), and it doesn’t smell at all when I get it out.

I think before I started using the diapers I cleaned the machine with bleach. That was over 5 years ago now and I can’t remember exactly.