Can’t activate SSL and wp-config.php file is not writable

Hello, we have the PRO version of the plugin, we tried reaching out via the support form but didn’t hear back, probably because I changed the email that’s pre-populated on the form.

Anyway, we have a lot of problems. We have a Bitnami instance on AWS Lightsail. I’ve setup all the permission correctly and even added all these to the wp-config file:

//Begin Really Simple SSL Server variable fix
$_SERVER["HTTPS"] = "on";
//END Really Simple SSL

//Begin Really Simple SSL session cookie settings
@ini_set('session.cookie_httponly', true);
@ini_set('session.cookie_secure', true);
@ini_set('session.use_only_cookies', true);
//END Really Simple SSL cookie settings

if (headers_sent($filename, $linenum)) {
	error_log("headers already sent in $filename, on line $linenum");
} else {
	if (file_exists(ABSPATH . 'wp-content/advanced-headers.php')) {
		require_once ABSPATH . 'wp-content/advanced-headers.php';
	}
}

and also this

define('RSSSL_FORCE_ACTIVATE', true);

yet, the plugin keeps showing this notice:

The wp-config.php file is not writable, and needs to be edited. Please set this file to writable.

Also, when I click Activate SSL, it shows “An SSL certificate has been detected” in the popup, and when I confirm, nothing really happens, it just show the next dialog. If I refresh, the button is still there, and even if I complete the whole process nothing changes.

Please take bitnami file structure into account, they have wp-config.php and wp-content in this path: /bitnami/wordpress and the actual WordPress installation in /opt/bitnami/wordpress with symlinks to wp-config.php and wp-content.

Finally, it seems that there is a Fatal Error sometimes when I visit /wp-admin/options-general.php?page=really-simple-security. This is not consistent and it happens on first load or plugin activation, but doesn’t appear on refresh. I don’t have the full error at the moment and it doesn’t appear now, but I felt it’s important to mentioned because it happened many times while I was trying to solve the problems above, making htaccess changes and apache changes to follow all the instructions.

By the way, I’m a developer, so I already followed all instructions available and read all related tickets, so hopefully you can help me while taking into account that I already tried most of the common solutions like file permissions, above edits to wp-config…etc