I always leave the door ajar after washes. Also the detergent drawer which I wash out regularly. Ive never run a programme without washing in though. but never had any problems yet and my washer in 30 years old !
i always leave my door open afterward too for a while, i also empty out the filter regular then put it on highest heat wash with nothing in so give these tips a try and see what happens
My wife always leaves the door open overnight,same with dishwasher,but she does take things out of them and clean them as well as using the proprietary aids to keep them clean