The password validation (e.g. for mail passwords) says:
In my specific case I had 9 characters, one uppercase, two digits and two special characters. This should be enough.
I guess the reason might be, that the special character I chose is not part of the given chars (what???). You should add more special characters to your checks - they are valid anyways - such as "+", "-", etc.
Ihr Passwort ist nicht komplex genug. Gemäß der Serverrichtlinie ist die Mindeststärke für Passwörter Sicher. Starke Passwörter müssen mindestens folgende Anforderungen erfüllen: acht Zeichen, ein Groß- oder Kleinbuchstabe, drei Ziffern und ein Sonderzeichen (!, @, #, $, %, ^, &, *, ?, _, ~) oder eine Ziffer und zwei Sonderzeichen.
In my specific case I had 9 characters, one uppercase, two digits and two special characters. This should be enough.
I guess the reason might be, that the special character I chose is not part of the given chars (what???). You should add more special characters to your checks - they are valid anyways - such as "+", "-", etc.