Here’s the fix for DH.
AddHandler application/x-httpd-php .php
Here’s a sample of a working HTACCESS file that lives on a site on DH (I have lots. this works)
AddHandler application/x-httpd-php .php
ErrorDocument 404 /missing.html
#EE index.php replacement file and folder method
RewriteEngine On
RewriteCond $1 !\.(gif|jpe?g|png)$ [NC]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ /index.php/$1 [L]
php_value memory_limit 64M
php_value upload_max_filesize 100M
php_value post_max_size 100M