It can take a while for learning to get integrated into your play and for things to actually "click."
In the process, trying to implement things you've learned can cause a loss in rating. Just keep learning and eventually you'll see the benefits if you're also actively analyzing your new play to help eliminate potential weaknesses.
Maybe it's just my disability progressing, but the more I practice, the more I watch tutorials, read material, do puzzles, and play games, my rating steadily keeps going down. There was a time I was beating 12xx players handedly, but now I blow massive leads, frequently blunder my queen away, and lose to very obvious and basic tactics. Anyone can go through my game history and see solid play and startling comebacks mixed with just absolute piss poor decisions. Some games I have 10+ blunders. Other games I come back from 10 and 15 point deficits. I feel my problem is I just can't see the board. It's kind of like driving. When you drive you pass hundreds of cars and signs, but you don't make a conscious note of what every sign is and what ever model each car is. In chess I can see pieces, I know every fundamental tactic, I practice strategies I learn from books and tutorials, I know I know far more chess theory and logic than when I was 13xx, but I just keep making massive mistakes. Even when I take time to think of a move, I'll literally come full circle and make the move I consciously decided was a bad move 60 seconds ago.
What the hell is wrong with me? I know more about playing chess than at any other time in my life and it feels like I'm worse than I have ever been. I make ultra basic devastating mistakes and blunder my queen away with terrifying frequency despite daily practice and studying. I feel like I just can't see the board. My brain sees every piece and knows in theory what they can do, but then I make a move and don't realize simple dumb shit like my queen is being attacked by a pawn my opponent just moved. What is wrong with me?
Tl;dr: I practice and study chess on a daily basis but my rating steadily drops with every passing week, what is wrong with me?