FB likes to rely upon structured data to determine which thumbnail to use. When there is no structured data, it guesses and often guesses wrong. I didn’t see any structured data on your post pages. FB likes OpenGraph structured data. Find a sharing or SEO plugin that adds OpenGraph tags to your post pages. They should set the featured image of the post as the OG tag’s image attribute.
The links that appear long and different have Greek letters and your links paste in with a bunch of % signs and hexadecimal characters, right? That’s normal because non-ASCII characters like Greek letters are not fully supported, so URLs are encoded to ensure full compatibility. They look like a hot mess when pasted, but they should render correctly in browsers. If you need to convert it back to proper Greek characters, there are a number of conversion tools online. Search for “urldecode online”. Realize that such decoded URLs may not work correctly in some instances.
Thread Starter
louel
(@louel)
Okay so you suggest me to use Latin characters instead?
Do you have any seo plugins to suggest me?
If you have trouble with Greek characters appearing in URLs and you wish to ensure full compatibility, the Latin representation of Greek would be a reasonable solution. This only needs to be done for object slugs, the title visible on the page can remain in Greek.
Yoast SEO is a very popular, well regarded SEO plugin. It adds both OpenGraph and Twitter card structured data to pages.
