With Helix Ultimate 2.2.1, the following URLs are used for Open Graph if Joomla is installed in a folder other than the domain root:
If local: /joomlafolderdomain.com/joomlafolder/images/blog/blog_02.jpg#joomlaImage://local-images/blog/blog_02.jpg?width=1140&height=640
If external: /joomlafolderimageprovider.com/images/my-image.jpg
These are incorrect.
In plugins/system/helixultimate/overrides/layouts/joomla/content/full_image.php, you have correctly implemented $toAbsolute(), which returns the absolute URL. However, in the open_graph layout plugins/system/helixultimate/overrides/layouts/joomla/content/open_graph.php, you are using Uri::root(true) on lines 29 and 44. If $toAbsolute already returns the correct URL, it's unnecessary to use Uri::root(true) again.
Additionally, in the past we had problems with Open Graph image URLs like these: https://domain.com/images/blog/blog_02.jpg#joomlaImage://local-images/blog/blog_02.jpg?width=1140&height=640, which weren't being shared on social media. That's why we have an override of full_image.php, and what we do is clean up the image URL so that it returns https://domain.com/images/blog/blog_02.jpg.
I'm attaching the two modified files for you to analyze. The important part is open_graph.php. Please fix soon
https://limewire.com/d/U2Xt9#lzwaiPhpHc
Regards