Thank you for your quick response, I just had a look at the suggested post, kindly see the comments for each recommendation below they are given in bold:
when you view the source of your page, the expected Twitter Cards meta tags367 are shown
NB at a minimum, your page must contain at least a twitter:card meta tag specifying a valid card type210 - I just checked it and it is there in our URLs.
if you execute curl -A Twitterbot at the command prompt, does your page still show the twitter:card tags in the section of the page? - Yes, it is there.
is your site accessible by the Twitterbot/1.0 user-agent? Are all the files (including image files) accessible to Twitterbot? you should check http://your-site-url/robots.txt241 and ensure that it allows access to our crawler. - Previously we were using only Twitterbot but now we have added Twitterbot/1.0 as well
are you using a Wordpress (or other CMS/blogging platform) plugin? We provide our own official Wordpress plugin201, but cannot easily provide support for those built by third parties. Check that the configuration includes all of the required tags. - Our site is using a WordPress platform, we are using another SEO plugin. It has added the meta tags perfectly. Do you think we should necessarily use the Twitter plugin?
are you putting the top-level site URL into the Validator, or the specific URL where your markup is present? you'll need to make sure that you provide a link to where your Card markup is visible in the page. Yes, it is.
are you using a supported53 Card type? Product, Gallery and Photo cards were deprecated in mid-201527. - No, I don't see it.
if your image is not showing, is it accessible on a URL that is not blocked by your robots.txt file? Does it conform to our size constraints? Are you using an absolute and full URL (including the http protocol piece), not a relative one? . Image is accessible when we view page source and access the image URL directly.
Should I share my site's URL with you?
Thank you indeed for your help. I really appreciate it.