I think i found the problem.
Try using PT
flag instead of L
flag because of your internal redirect on symlink.
This way, it is re-evaluated
RewriteCond %{QUERY_STRING} ^_escaped_fragment_=/?(.*)$
RewriteRule ^(.*)$ /%1? [NC,PT]
EDIT: You have to reorder your rules. Your htaccess should look like this
<IfModule mod_rewrite.c>
<IfModule mod_negotiation.c>
Options -MultiViews
</IfModule>
RewriteEngine On
RewriteCond %{QUERY_STRING} ^_escaped_fragment_=/?(.*)$
RewriteRule ^(.*)$ /%1? [NC,PT]
# Redirect Trailing Slashes...
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)/$ /$1 [L,R=301]
# Handle Front Controller...
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^ index.php [L]
</IfModule>