Debian11默认配置Apache2.4访问/.htm/.html返回403而非404的原因求助

大家好，我碰到一个挺奇怪的Apache问题，想请教下各位：

我在Debian 11上安装了apache2，全程没修改过任何配置文件，用的就是系统自带的默认配置。但测试的时候发现了一个异常情况：

• 当我访问http://localhost/.htm或者http://localhost/.html这些不存在的文件时，返回的是403 Forbidden状态码，而不是我预期的404
• 但如果访问http://localhost/.abc这类其他后缀的不存在文件，却能正常返回404 Not Found

有没有大佬知道这是为啥呀？难道是默认配置里有什么针对.htm/.html后缀的特殊规则吗？

下面是我的默认虚拟主机配置：

<VirtualHost *:80>
    # The ServerName directive sets the request scheme, hostname and port that
    # the server uses to identify itself. This is used when creating
    # redirection URLs. In the context of virtual hosts, the ServerName
    # specifies what hostname must appear in the request's Host: header to
    # match this virtual host. For the default virtual host (this file) this
    # value is not decisive as it is used as a last resort host regardless.
    # However, you must set it for any further virtual host explicitly.
    #ServerName www.example.com

    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/html

    # Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
    # error, crit, alert, emerg.
    # It is also possible to configure the loglevel for particular
    # modules, e.g.
    #LogLevel info ssl:warn

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    # For most configuration files from conf-available/, which are
    # enabled or disabled at a global level, it is possible to
    # include a line for only one particular virtual host. For example the
    # following line enables the CGI configuration for this host only
    # after it has been globally disabled with "a2disconf".
    #Include conf-available/serve-cgi-bin.conf
</VirtualHost>

备注：内容来源于stack exchange，提问作者byteunit