Here are a few tips that may help you resolve this problem:
1. Check the water fill level in the dishwasher. Start a cycle and allow the dishwasher to fill. As soon as the filling stops, crack the door open to stop the cycle. Open the door fully and look at the water level in the bottom of the tub. It should be within 1/4" to just touching the bottom of the heating element. If that water level is too low, you can check the water supply provided to the dishwasher.
Shut off the house circuit breaker for the dishwasher and turn off the water supply before accessing that water supply tube. You can disconnect that water supply tube and place the end in a shallow pan or container. Briefly open the water supply cut-off valve to check the water pressure and flow that comes out of the end of that line. If the water supply is inadequate, you will probably need to have a plumber fix that type of problem. If the water supply is okay, you could have a clogged inlet screen on the water valve or a failed solenoid inlet water valve assembly.
2. If the water level is okay, you could have a problem with the upper spray arm or the supply manifold. Check the upper spray arm for cracks or splits. Check the holes in the spray arm for deposits or debris. You can clean those holes with a toothpick or bamboo skewer if necessary. If the spray arm is okay, make sure that you are pushing the top rack all of the way back into the docking connection for that upper spray arm when you start the cycle.
3. A clog or restriction in the chopper blade area of the sump has been known to cause poor cleaning of the upper rack dishes in this type of dishwasher. The image below shows how to access that area in the sump. Your dishwasher may be slightly different than the one shown below but the basic access procedure is the same. If you find debris or a foreign object in the chopper blade area, then clearing that type of restriction may resolve your cleaning problem in the dishwasher.
I hope these tips help you.