Odor is present within washing machine. It smells stale.

Front Loading machines are notorious for odors. There are cleaners made to help remove the residue that builds up on the outside of the drum and causes odor. One thing that you can do to help cut down on odor is to leave the washer door open slightly when not in use. Closing the door prevents the drum from drying and allows the formation of the residue that causes the odors.

A lot of machines can suffer from this problem. It is usually down to a bacteria build up between the drum and the tub. The majority of appliances that suffer form this have been used mainly on 40 degree washes and with a biological detergent.
The best way to get rid of this smell is to place two tablespoons of washing soda or soda crystals in the detergent drawer and then run the appliance empty on the 90 degree wash. You may have to repeat this treatment before the smell goes but it will go eventually. Hope you've checked out & cleaned your filter.
You can give me a ‘very helpful’ rating for the help, can't you. Thanks.

Apparently it's a common fault (among others) with this brand/model of washer; as Whirlpool has dedicated a page to it.
How to clean the interior of your washer to remove odors

Front loaders are known for building up mold and the smell.
It’s caused by using liquid detergent which is made from animal fat. Use powder. And use the minimum amount.
It’s caused by using fabric softener. Dilute it 50/50 with water.
It’s caused by the water remaining in the tub between washes. Leave the door open to allow it to dry. .
Pull the rubber door seal back and clean the mold off .
Affresh is recommended by some manufacturers. You run it through a wash cycle with it.

Front loaders are known for building up mold and the smell.
It’s caused by using liquid detergent which is made from animal fat. Use powder. And use the minimum amount.
It’s caused by using fabric softener. Dilute it 50/50 with water.
It’s caused by the water remaining in the tub between washes. Leave the door open to allow it to dry. .
Pull the rubber door seal back and clean the mold off .
Affresh is recommended by some manufacturers. You run it through a wash cycle with it.

This is normally a build up of dirt within drum....You could try boil wash on its own or buy a cleaning agent for that purpose/ also check sink is clean @ drain hose end. this can cause problems..Happy wash days....Good luck

Keeping the lid shut is one of the worst things you can do for a washer. Obviously, the company you spoke to does not know what they are talking about. It is strongly recommended that you leave the lid OPEN when not in use in order to ventilate the wash tub and allow it to dry. There is always a small amount of residual water in the drain pump and lines, however, that will not evaporate. With the lid shut this residual water can sour and cause odors.

Consumers that do not normally use a HOT water cycle, do not use bleach, or run the washer infrequently can also experience odor problems with mildew and odor. It is recommended that you run at least one HOT cycle per week, or run a cycle with bleach when washing whites to keep bacteria and odors to a minimum. I hope this advice helps you. Let me know if you require further assistance.

Most commonly, this relates to sulfides or other impurities in the water itself, but may also be caused by a buildup of food soil within the washer. Smell a clean glass of water. Does it smell stale also? If no, clean the screens and wash water sump/tank within the machine.
You can also clean the inside of the machine by using a commercial grade dish machine detergent and increasing water temp if possible.
If the water smells stale, consult a local water expert for guidance in resolving

If the washing machine itself smells bad when you open the door, it could be that it's covered in a horrible grease and gunge inside all the hoses and the tub. This particularly affects older washing machines and is common with washing machines that have only really been used at 40° or where only liquid detergent has been used.

Not using enough soap detergent over a long period of time can cause a build up of grease and therefore bad smells.
Get rid of washing machine smells

You could try to clean the washing machine inside using Soda crystals which dissolve grease. I recommend putting half a packet inside the drum and washing on a boil wash (or follow instructions on the packet) Using this method every month or so, or using ordinary detergent if no soda crystals are available can help prevent smells from your washing machine. If your washing machine is badly affected by grease and slime, it may be very difficult to remove it.

Get rid of washing machine odours using vinegar
White distilled vinegar has an array of uses. For bad washing machine smells, try putting half a cup of white vinegar inside an empty machine and put it on a boil wash. Because the first bit of water goes into the sump hose and is sealed off, I recommend that you wait until the washing machine has been filling for about 30 seconds and then pour the vinegar into the soap drawer to let it wash down into the machine. I've had reports back from people that this does actually work.