You look to be using a security product that is blocking Twitter from crawling your page.
This may be technical, but if I run the following command to fetch your page -as Twitter-, I get a 'content blocked' page:
curl -v -A Twitterbot https://pagefromyoursite
The HTML comes back with some code like:
<p><a href="https://www.siteguarding.com/" target="_blank" style="font-size: 12px;">BadBot protection by SiteGuarding.com</a></p>
There's a lot more to it, but I'd recommend checking your hosting or security settings to allow Twitter to crawl your site.
I hope that helps!
Alex