It happens often where you paste the link into your status update for your personal page or business and the thumbnail doesn’t appear or the wrong one appears.
1. Simply paste the link you’re trying to post into Facebook’s Debug Tool.
2. Then go back to your Facebook page and try to paste the same link again and the thumbnail should appear.
I don’t know why this works, but it does for me. I don’t even have to do anything other than that!
Hope that helps!