I just bought a used. I just bought a used Kenmore standalone dishwasher and ran it for the first

Question

I just bought a used Kenmore standalone dishwasher and ran it for the first time. The dishes on the top did not get clean and the soap did not come out of the closed soup dish. at one point I took a shower and was wondering if that might have influenced the water pressure enough to cause the problem. Is the soap supposed to open during the wash and could the poor water pressure prevent the top shelf from getting properly washed?