There are a few videos on puzzle design over on the Game Maker's Toolkit YouTube channel. He even did a devlog series on the development of his own puzzle game, which may help!
You don't need to watch every video if you don't want to. Not all of the videos are applicable to the puzzle design of puzzle games, but honestly I have been subscribed to them for as long as I can remember, and a lot of my understanding of game design came from them.