MAC Preview has automatically added password to 3 x pdf's
I've been using MAC Preview to update/edit several pdf's.. and of course whilst working on them automatically save them using Command S. Now for some reason, all the documents have passwords on them to open the documents, and I have absolutely not password protected them at all (yes am adamant).
Any ideas? I need to open the documents and have no idea why there is now a password protection on them that I have not created.
Thanks.
MacBook Pro 14″, macOS 12.6