Why is it that military sci-fi writers feel they must occasionally write for 13-year-old boys experiencing puberty?
I've seen this happen in other series. Often it just happens once and then the publisher sit the author(s) down and has a talk with the author(s). Sometimes they don't.
Fortunately, while this story started off at the wrong level, it gradually became better. There wasn't a tremendous amount of action in this book compared to others in the series, but I still enjoyed it... after getting past the first few chapters. And, the wrap-up, after the climax, was a bit to simplistic. The authors can do better than this.