problem with adAuthenticator - non printable characters added to username

[Peter Schober]

Marcin Rożek via users <users at shibboleth.net> [2026-07-28 11:31 CEST]:
> But attribute resolution fails because something somehow adds
> non-printable characters %0A%09 at the beginning and %0A%00 at the
> end of username provided by user:
> best match of:%0A%09's000003 at domain.pl'%0A%00

And that consistently happens all the time, with all users?
Just one?
-peter