1. Dishwashers in North America don't work well due to our 120V power. You often end up washing with cold water for that reason, not enough watts to get the water to the proper temperature. The cleaning agents & enzymes in the detergent require heat to do their job. Prior to starting the machine I run the hot water tap, flushing the cold water from the line.

2. I have hard water in my location. I put a ½ a cup of vinegar in every load now. It helps the cleaning work better, and stops scale from building up in the machine and making it less efficient.

Once I started doing this I've never had issues.