Just installed MacOs Sequoia. All goes fine. Suddenly all my PDF documents required a Password never set

I have never had problems with my documents. Never set a password on over neither of them. And, if the case, I have been always entitled to do everything with my master password in my computer. Suddenly, an invisible hand has set a password over documents created months or years before. So, I cannot now, read hundred of important documents. Is it for an Adobe question or for an Apple one?