Sorry, I was pretty sure I replied to you right away but I can't find the message.
Anyway, your host is NOT accessible from the outside world (I just tried again and I can't curl to it). Actually your main host is, but when I access the WebDAV url I get redirected to an internal host (some IP address on 192.168.*.*)
If you can't host your WebDAV on an externally facing server you should setup your current externally facing server as a reverse proxy for your webdav server.