I host a website on Azure (Web App), but in front of it there is a reverse proxy server (Win Server 2012R2, IIS 8, ARR 3) to route
/blog requests to another server.
If I try to share an url (
example.com), there is no preview. But if I share original url (
site.azurewebsites.net), preview works fine!
Reverse proxy configuration is default one, latest ARR addon with one rule, routes to server farm with one server. I do not block anything, just rewrite all request to
site.azurewebsites.net. IIS logs looks ok, Facebook bot receives response status 200.
Also, in facebook debug tool (https://developers.facebook.com/tools/debug/og/object/) all tags and HTML are read correctly, but there is no preview on the bottom.