On Mac, If the user registers the Password and the Software Authenticator app for a website like PayPal then uses the Safari browser to login the Apple system is creating confusion.
The system prompts to use the authenticator autofill for any grid like SMS OTP or even for the Email OTP. That creates confusion for the user as the SMS OTPs or other OTPs cannot be validated by auto filling the Authenticator TOTP. That fails the validation resulting in bad user experience.
The system should not prompt the Autofill from the Authenticator app unless the grid box shown on the page was for the Authenticator app.