Hi Yannick
Joomla 3.10.11 & PHP 7.3.33 apache 2.4 Ubuntu 22.04
I contacted you yesterday but posted in public forum - sorry!
I have both 4SEO and 4SEF on my site https://example.com
I had an issue with a White Screen of Death which was caused by "To many redirects". I discovered that if I entered "index.php" to the end of my base url my site worked. I assumed there must be some form of redirection in my apache setup or in .htaccess file (admintools). I checked the apache setup and vhost .conf files and replaced .htaccess with a default vanilla joomla .htaccess file. This did not work. I therefore put in place a redirect in the vhost file "RedirectMatch ^/$ /index.php" which diplayed the home page correctly (base URL was https://example.com now displayed as https://example.com/index.php).
However I now get 404 errors on all other pages.