As for the second movie, I think that the ending reflects the personal evolution of the main character, Cyril. Thus, all he wanted is to find his father, but the experience that he gained in the course of it contributed to his personal evolution. In other words, at the end of the movie he was able to develop a broader picture of the world and not limit his perception with the ideas which shaped his character in foster care.
I believe that the ending of the first movie is a satisfying resolution to the events that lead up to it. If one takes a close look at the situation, one will be able to see that Sandra did not want to keep her job, just like other people did; she objected the lack of justice which happened in the work place. So, when we was presented with a choice to keep the job, but allow the injustice to continue, she, being faithful to her original desire, decided to resign.
The ending of the second movie is also insightful: with the help of it the viewer is able to see that Cyril did not only try to find his father, he wanted to discover the new aspects of his personality and in the end, the audience is able to see that he made a giant leap in personal development.
It is quite obvious that there is a peculiar relationship between the two endings. Thus, they both allow the characters to achieve the goal which they truly wanted, in spite of the fact that they may not have realized it.