Source: Facebook image size best practices. Once you’ve upload the correct image size, use the debug tool in solution one and tell Facebook to “Fetch new scrape information”. Then try to share your page again on Facebook. Hopefully it’s working. If not, move on to solution three. Solution 3. Help Facebook find the correct image
https://mysiteauditor.com/blog/how-to-make-facebook-show-the-correct-thumbnail/

