Hello all, first time poster here.

I have a GE dishwasher (don't have the model number at hand). I've noticed the cleaning tablet in the dishwasher is about 95% dissolved at the end of the cycle. I was investigating and noticed at the back of the dishwasher inside on the wall, there is a water pipe with two holes. One connects to the upper spray arm but the one below it had a white plastic thing. I pushed it in and it was a little sticky, but it dislodged and then I realised it seems to be a small white ball. Can anyone explain what this is and it's function? I'm assuming it's used to divert the water to the top and bottom arms?

Maybe related, I've been noticing the water pressure to the kitchen sink is low too. The dishwasher water supply line branches off from the kitchen sink and this might have something to do with it.