If you set the password with NFC Tools, then the only way to remove the password is with NFC Tools. You have to get it 100% correct, case matters, whitespace matters too IIRC.
NFC Tools does some password-mangling or something so no other app or utility will work. It also protects the entire tag as read-only, so it cannot be written to without the password.
I suggest you keep using NFC Tools to try removing the password. Good luck.