Hi there Yathosho.
I′ve found the problem, but not the solution, after an insight based on a word in your comment number 2.
Here is the devil word and the key to my problem: EMBEDDED.
The theme I′m using with WordPress is called Dance Floor DJ and it is from https://gorillathemes.com.
The theme features a function inside the post edit tool where I have only to add the Youtube/Vimeo video ID and it automatically put it as a feature article, correct the sizes, etc.
Here is the sample post: https://www.topradiosbrasil.com/?p=1432. In this post I have put the video ID inside the tool and also put the Youtube video link before my post.
Doing that, I mean, not using the video ID tool, your plugin works perfectly, the OG:image is generated and everything is OK.
But now I have a problem, if I choose not to use the tool, the size of the video don′t match the post size (as you can see in the sample post) and my post in my main page (index.php) don′t show the video, only the link to the video.
Any ideas how can I fix that without open a ticked with Gorilla Themes?