Agreed. The puzzle difficulties seem to be all over the place. Some of the trouble I've had is ambiguity, which I think is poor puzzle design. I already mentioned puzzle i. In puzzle m, I could justify a wide range of possible answers, and I picked the correct answer only because I knew the other answers have been simple, short words.
It seems that most of these puzzles fall under the category of, "figure out how the designer encoded the information." I've done a couple escape room this year, and most of the puzzles are like this, but ambiguity is a real problem for these types of puzzles.
I'm more used to logic puzzles like l, where the rules are spelled out, and the goal is to find a solution that satisfies all the rules.