Miele dishwasher middle and lower spray arms have stopped working. Arms have been cleaned, and spin freely. Filters have also been cleaned. Circulation pump was replaced about a year ago due to leakage. It appears that water is not presently being supplied to the lower arms. I saw an earlier discussion of a stuck Top Solo Valve causing a similar problem in a different Miele DW model. I am trying to figure out whether this model has such a valve, or whether it is integrated into the circulation pump; and whether it can be unstuck or must be replaced. Thanks in advance.