Powermail (7.4.0) default Captcha keeps failing with TYPO3 9.5.7

Question

I am trying to configure captcha field with powermail. It always throwing error Captcha: Falscher Captcha Code eingetragen, bitte erneut versuchen!, I tried to investigate the causes of the issue. I found if I remove below rewrite rule from .htaccess

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-l
RewriteRule ^.*$ %{ENV:CWD}index.php [QSA,L]

...then it's working correctly and form submission will succeed. But, this will lead you to another problem. As rewrite rule above redirect you to index.php if the file/symlink/directory does not exist, So this won't work. Now, your home page will work fine but inner pages will lead you to 404 error.

See:

Here is my apache configuration for virtual host:

<VirtualHost *:443>
    ServerName www.relaunch.typo-site.de
    ServerAlias relaunch.typo-site.de

    <Directory  "/var/www/html/relaunch">
            AllowOverride All
            Order allow,deny
            Allow from all
    </Directory>
</VirtualHost>

Can anyone help me with this? I found a similar open issue at the Github repository.