This can happen with any front loading washer, regardless of the manufacturer.
One of the first things to do is make sure you're using the He (High efficiency) laundry detergent and only use a small amount, about 3 tablespoons or less. The trick is to not use so much detergent that you start getting a buildup in your machine. Also, if you have heavily soiled clothes, pre-treat them instead of adding more detergent to your wash cycle. This alone will result in better results.
Also, be certain the washer is properly leveled in all directions and to make some slight changes in your wash day schedule.
By making sure the washer is properly leveled, it will operate better and help minimize odors, as the spin cycle will get more water out, etc.
The other tip, that has really helped in our
house, is to do all the hot water (whites) as the last load. Since we do use bleach when we wash our whites, along with hot water, the washer's last load will have had the best sanitizing cycle run through it before being left for the next load another day.
With the bleach and hot water, the washer gets a nice clean disinfecting wash which helps eliminate odors, germs, excessive soap, etc. and leaves the washer fresher. By doing this, we don't have to purchase other (more costs and expense) additives to run through the washer to attack the odor causing germs and gunk.
What good is a more energy efficient washer if I have to always run a special tablet/liquid cleaner in it each week without any laundry in that wash load? Seems wasteful to me to be doing an "extra" wash just to wash the washer. So I'm not a proponent of having to always use another product every week or month to have a washer work like it should.
However, if you've got an existing (smelly/moldy) washer presently, I would recommend that you use a produce called Whirl-Out, which will help dissolve the buildup that your machine currently has and get it clean again. Then you can follow the steps above to keep it from causing you issues in the future.
I hope you find this Very Helpful and best regards!