I was on Drupal 8.5.x and Twitter cards and Open Graph on Facebook were displaying correctly.
After updating to Drupal 8.6.1, the images don't display anymore. The others data (title, description, url...) are OK, it's juste an images problem.
So I've checked the tokens used by the Metatag module and they are the same I used in Drupal 8.5.x without any problem.
The token I use for images is : [node:field_image_article:entity:field_image] Indeed, in my content type, I use a field named "Image article" that contain several fields (title, author, licence...) including an "Image" field where I upload the image.
When I look at the source code of my webpages, I have this :
<meta name="twitter:image" content="https://example.com" /> <meta property="og:image" content="https://example.com" />
instead of the complete URLs of the images...
Does anyone know how to solve this ? Thx.