TYPO3 Core

A 404 error like an unknown link redirects to a 404 page of the local website. The website is shown to everyone.
The local server runs under ddev and a apache-server is defined for the local website..
The redirect works as expected, if a unknown error occur..

As soon as I restrict access to the website via .htaccess and .htpasswd, I would get the attached error page instead of the 404 page.

Paste into .htaccess

AuthUserFile "/usr/www/users/myAbsolutePath/current/public/.htpasswd"
AuthName "Realm"
AuthType Basic
require valid user


And paste in htpasswd (user:test password: Test123!)

test:{SHA}lq/Xq6QG6tQ7o9YrLA+WYi5LLJM=


I would have expected the 404 page to keep popping up on broken/unknown speaking links.