Two different URLs render exactly the same content, but Card only shows in one tweet


I have two URLs with exactly the same content. Both URLs are valid using the validator and the previews are good. However, when I tweet them, Card only shows in one of them. Is it related to the cache thing?

Here are the URLs:
This one doesn’t show the card. See the tweet here:
This one displays the card correctly. See the tweet here:

Any ideas? Many thanks!


It suddenly worked yesterday but broke again today. I deleted the two links above so please refer to the new links below. It’s kind of urgent. Really appreciate if anyone has an idea about what the problem is. Thanks a lot!

This one didn’t work. (

This one works. (


The card for works again after about 12 hours.

However, the bitly version of the same URL ( is not working. Or it will work after a few hours?

My question is still that why the two URLs behave differently. Also, if it’s something related to caching, how can I force it to load the latest version, for example, the Facebook Debugger?

Thanks a lot for your help!


Hey, is there anyone who can help me take a look?

Based on what I observed, the URLs pointing to work sometimes but broke randomly. For example, it was broken last night, was working this morning, but broken again now. It really confused me because I didn’t modify anything. The tweets are here:

However, the URLs pointing to always work. As I mentioned above, it is exactly the same content as, so I really don’t why they behaviored differently. Here are the links:

Any ideas? Many thanks!