I am a java developer, I use the twitter4j-core to send the message like " xxxxxx http://mysite",I also set metdata values of twitter cards in my website page header like:
<meta name="twitter:card" content="xxxxx" />
<meta name="twitter:site" content="xxxxxxx" />
<meta name="twitter:creator" content="xxxxx" />
<meta name="twitter:title" content="xxxxx" />
<meta name="twitter:description" content="xxxxxx"/>
the cards don’t display every time , sometimes it hides,what is the problem???