How to add Support to show Fullwidth Featured Image of Custom Post Types in WordPress.?

This happens when the image does not have a specific width/height.
The image you try to load in your custom-post-type is too small (379x354px). So LinkedIn, Facebook or others will use the layout with the smaller image.

Facebook says:
Images that are at least 470×246 pixels will display as a rectangle with the title and description below. Images that are smaller than 470×246 pixels will display as a square with the title and description to the right.