Manhattan was made in 1979. VCB in 2008. 29 years is a long time. When the core of the movies of resemble each other, it only leads me to believe that Woody Allen hasn't found a convincing answer for his questions in these 29 years. This kind of repetition is probably unavoidable when you are an honest artist struggling with an impossible puzzle.
(I realise there's another possible explanation. VCB does have some solution for the puzzle, only I fail to see it.)