This might be a long one so hold on.
First off I read the book before I watched the movie, I don't recommend doing that, it will definitely spoil the movie.
Things that are a bit off/annoying
1. The connection between John and LJ was not there. In the book I really felt that LJ could almost fall in love with John and not Peter but in the movie I didn't see any chemistry between the actors and it was all together cringe.
2. The boys acting got way worse. In the first film I liked Peter so much better. He over all wasn't as cringy and it made me enjoy the story more. there wasn't a scene with Peter or John that didn't make me wince.
3. They missed so much of the good parts. In the book there's a lot more with LJ and Peter being broken up and it makes them getting back together much more satisfying.
4. It didn't make me feel the same as the first movie. The editing and script was so much better in the first movie so it made it much more realistic. The second film was made much more of a cheesy cheesy Netflix romance.
5. The whole hot tub drama with Peter waiting for Jen. In the books Peter tells LJ he likes her before he goes to the hot tub, and LJ knows she likes him back right there. After LJ rejects him he's probably just looking for another girl to kiss, not trying to get them both. It's really not that big of a deal and the movie portrays it a lot different.
Will I still watch the third movie? Yes. Do I sometimes still watch this movie? Yes, but it always leaves me disappointed.