I purchased a set of what were supposed to be higher end LG appliances from Costco which were installed in January and February 2019 (long story of receiving grossly defective equipment at time of delivery and also installer error resulting in several appliances being replaced more than once). Still our LDT7808BM has been the worse performing dishwasher we have ever had and I believe our conditions are almost ideal. We have always had to pre-rinse dishes with this dishwasher, more so than any other. We run our softened hot water through the sink before turning the dishwasher on (have never had to do this with any other machine) and our water is hot. We used high quality detergent as rated by Consumer Reports and also use the rinse aid. I have done the troubleshooting steps many times and there is rarely any debris in the drain trap and all the spray arms are not blocked in any way. Today I notice that this rubber part (almost like a sleeve) that goes from just behind the lower spray arm and connects to the metal channels going up to the upper spray arm looked a little bit off. Upon further inspection, this part is fully not connected in the holes and pushing the part into the holes makes it just pop right back out. It also comes up high enough that it affects the lower spray arm from turning. I'm certain this is my issue and have a call in to hopefully have a tech come out whenever they call me to schedule. However, I did want to give the repair person a heads up on what part I think they need, but am not finding any parts schematics online.
Does anyone know what this part would be called and the part number? Does anyone know this part to have a chronic issue (it sure seems like that could be the case).