Won’t allow password change

Thanks for the idea. I tried it, it did not work. I can change the password on the website directly and the new password saves and works later. The keychain saves both passwords, old and new, in two separate entries even though it’s the exact same website URL. The old password doesn’t get replaced. When I try to manually delete the old password it reappears within a minute. I’ve manually deleted both the new and old passwords and the old one reappears, never the new one.