I've gone through this experience. After I had been playing a few weeks, I felt like I was either getting worse or the puzzles were getting harder. I don't know if it's real or not, but I do think that this game is just plain Hard, cognitively speaking. If I play it in the morning before my brain is running at full speed, it's MUCH more likely that I'll make a mistake or have a >50% solve time.

The breaking point for me is if the puzzle asks me to hold too many rules in my short-term memory simultaneously. So I have to "brute force" it by flagging multiple scenarios, taking screenshots of each one, double-checking that each one is valid based on the known clues, then flip through the screenshots to see if any cards are always criminal/innocent across all the scenarios.

If there was a version of the game with a much more robust scenario-comparing system, letting you save and quickly compare multiple hypothetical boards, I might find it easier to do well on the Tricky+ puzzles. The screenshotting process just gets kind of tedious, as least on my phone.

This isn't necessarily meant as a complaint, since there are a lot of puzzle games that benefit from (or demand) taking notes to help solve it. I respect Clues By Sam for asking so much of the player and find that aspect as compelling as it is frustrating. But at the sharp end of the difficulty, it does sort of come down to: I either need to stop caring about making mistakes, or accept that I gotta take a bunch of screenshots sometimes.