From your own link, emphasis added:
In SP 800-63B, NIST has not explicitly recommended the use of password managers, but recommends that verifiers permit the use of “paste” functionality so that the subscriber can use a password manager if desired.
So NIST is saying that not permitting the use of "paste" is to disallow the use of a password manager. As other contributors to this thread have pointed out multiple times.
Your message is ambiguous; it's not clear which behavior you refer to. I hope this clarifies it.
