ChatGPT Goes Stupid- Help me

Hello, I’ve had a problem for several weeks, and today it’s hell. ChatGPT refuses to work, he refuses to write correctly while respecting the instructions, he does what he wants. If we ask him to respect a key word, he changes it and then he apologizes for having made a mistake, that’s all he does. with 40 posts I can’t even get a decent article. The more ChatGPT is updated, the more it regresses. It’s becoming hell to work with it, it’s getting worse every day. The service is becoming deplorable. Don’t say this is from my custom instructions because these have been the memes for months and my prompts are the same and they all worked perfectly before.