@44W74l4
As I said this is one of the principles of the basic melody design (cantus firmus). If you draw a melodic line and form a tritone (augmented 4th), a split occurs. The upper note B wants to resolve to C (ascending), and the lower note F wants to resolve to E (descending), as happens with any tritone. And this is not what happens.
In other contexts with more complex textures, perhaps all this is much more relaxed, although it is still an essential principle. But in this kind of works where the voices are clear, the effect is more noticeable.