What is the reconciliation between the permissibility of a trace of impurity remaining after washing in an automatic washing machine, and your statement that all clothes become impure if a trace of feces remains after washing in it? And is it necessary to seek out the trace of impurity after washing in an automatic washing machine?

There is no contradiction between the two fatwas. The first pertains to water into which impure garments have been placed. It mentions the view of the Malikis and the majority, with the majority's view being preferred, but permission is granted for the scrupulous (one afflicted with whispers/waswas) to adopt the Maliki view as a concession. As for the second, it discusses water that has come into contact with impurity. In this case, neither the water nor the other garments in the washing machine become impure, as long as the water has separated from the impurity without changing.