Hello,

Since upgrading to Joomla 5.4.3 today, frontend login no longer works when both SEF URLs and mod_rewrite ("Use URL Rewriting") are enabled. The login form submits and silently redirects back to itself, with no error message displayed.

Environment:

• Joomla 5.4.3 (issue appeared immediately after upgrading from 5.4.2)
• SEF URLs: enabled
• Use URL Rewriting (mod_rewrite): enabled
• Add Suffix to URLs: disabled
• Session handler: Database
• force_ssl: 2 (HTTPS enforced site-wide)
• live_site: set to https://
• Standard Joomla .htaccess file, unmodified
• All Multifactor Authentication plugins: disabled

Symptoms:

• Frontend login fails silently for all users (redirects back to login form)
• No error message is shown
• Backend login works normally

Workarounds confirmed:

• Disabling "Use URL Rewriting" (mod_rewrite) restores frontend login for super user (only), but index.php appears in all URLs
• Disabling SEF entirely also restores login

This worked perfectly in 5.4.2. Nothing in the server configuration has changed. The issue is clearly a regression introduced in 5.4.3.

Thank you for looking into this.