The Little Lady Agency and the Prince Book

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First, not enough prince. The books is called The Little Lady Agency and the Prince. But the prince storyline get buried between angst with the fiance and drama with Melissa's family. He appears almost at random for such a titular character and feels like just another thing thrown in to delay Melissa and Nelson finding love. Basically, the prince needed to exist for that scene on the yacht where Melissa realizes what a dependable guy Nelson is. But for her to be on the yacht, the prince needs to appear earlier and make her feel confused. So he does. Sort of. And floats around when convenient.
I didn't like the way Melissa reacted to the prince. She gets all gooey around him because he's hawt. Like, come on, girl. Have some more self-respect. But I could almost say the same thing to the prince. He changes far too fast for it to come across as believable. In fact, almost to the very end, I expected his improved behavior to tie in with a giant prank he intended to play on her. But no. Apparently it was genuine? Why? There was not enough development there for me to believe it.

Second, and of course the biggest elephant in the room, Melissa begins the book engaged to one chap and ends making out with another. Nelson obviously rocks. He's perfect for Melissa and is basically Mr Kightley so what's not to love? But mostly I just feel bad for Jonathan. He totally gets derailed and it feels out of character.
I read The Little Lady Agency four years ago and though I forgot most of it, it did stick with me as a book that surprised me with the romance. The boy-next-door doesn't win the girl. The American does. The redheaded American. Win! Totally a fan.
But it quickly became clear as I read this book that Jonathan no longer gets the girl. He has 0 personality. His workaholic nature--always a plot point--now becomes his only point. And he does some really kind of...shady stuff behind Melissa's back. Which made no sense.
This isn't the guy we met in the first book.
And while Johnathan continues to lose his personality, Nelson just gains more. He's the ever-present, developed, reliable character at her side. If this started the series, you would see the switch in her affection a mile away.
But you see, we already went over this. In book one. She chose Jonathan. Now Nelson?
I guess this just circles round to why I don't like love triangles. And love triangles that continue over a trilogy and switch it up...even less enjoyable. (hide spoiler)]