Argument #1 ($uid) must be of type int

Problem/Motivation

When creating a new user manually, this error ocurrs:

TypeError: Drupal\externalauth\Authmap::get(): Argument #1 ($uid) must be of type int, null given, called in /(...)/modules/contrib/simplesamlphp_auth/src/Plugin/Validation/Constraint/SspaProtectedUserFieldConstraintValidator.php on line 71 em Drupal\externalauth\Authmap->get() (linha 57 de /(...)/modules/contrib/externalauth/src/Authmap.php).

Steps to reproduce

With simpleSAMLphp installed and working fine, try to create a user manually.

Proposed resolution

If I change the config /admin/config/people/simplesamlphp_auth/local and activate "Allow SAML users to set Drupal passwords", then the error goes away.

I would like to hide password from user edit, but if this blocks manual user creating, it could be documented.