Hi, it is weird that the password is not accepted. Please ensure that you are entering correct password. Also there is now an issue with Samsung Pass, I'm not sure but it cannot be affected. Please check the password and wait until Samsung Pass issue is fixed and then try again.
There is no method how to recover password because it is not possible. The password is used as an encryption key and it is not stored anywhere in readable or changeable form. If you lost the password, you lost the data. But as I'd write above, please wait (my Secure Folder works well but I use PIN, not a password there)