Problem with Facebook OG image

It seems you’re using the WebP Express plugin to convert your images to the WebP format.

I don’t know how the plugin works, but I can see the converted images are placed into and served from a separate folder /wp-content/webp-express/ — and the original JPG/PNG image URLs in the /wp-content/uploads/ folder no longer work.

I can’t say if the original images get deleted or not — but their original URLs are all returning 404/Not-Found).

Meanwhile your Yoast SEO plugin isn’t aware of what’s going on… and continues to use the original (but now broken) image URLs in the Open Graph og:image tag. That’s why you’re not getting any thumbnail images.

If you want to continue to use this WebP Express plugin, I’ll recommend you post in this plugin’s own support forum to get help from the author and user community: https://wordpress.org/support/plugin/webp-express-plus/

Good luck!