Currently for my blog, the Twitter Cards (Summary) that I have setup seem to only work intermittently. In most cases the card appears with no thumbnail image. In other cases the thumbnail appears.
Example of working card: https://twitter.com/TheMarke/status/384769625625350144
Example of working card without image: https://twitter.com/TheMarke/status/384860269177868289
It doesn’t seem to matter how big the original image file is or how big/small the dimensions are. It seems to be quite random, working for 3 or 4 posts in a row then going back to not working.
There are also some cases in which the Twitter Card doesn’t appear at all when the post link is first tweeted, but appears later on (maybe anywhere from 5 minutes to 2 hours later). Or the Twitter Card appears correctly immediately then suddenly disappears from those same tweets.
Example of tweet that once had Twitter Card but now no longer shows it: https://twitter.com/TheMarke/status/385132069837238272
Validator has also shown either all green or sometimes there’s a Invalid image or Fetching the image timed out error for the twitter:image section.
Is there any way to make the Twitter Cards more consistent on my end?
I use Wordpress for my blog at www.themarkeworld.com. I have used the Wordpress SEO and/or Twitter Cards Meta and/or JM Twitter Cards Meta plugins all with similar results. I have also setup my robots.txt file to allow for Twitterbot per the Twitter Card instructions/documentation. I am however using a virtual robots.txt file. Does that even matter? Also, should the user-agent for Twitterbot be moved to the top of the file?
Thank you for any assistance you might be able to provide.