Ghost image

There is an image showing as a thumbnail on my Applications page for the wine post
https://nir-for-food.com/applications/
But the feature image for wine is different than what you see on the Application pate. It is what you see on the post page
https://nir-for-food.com/wine/

Why isn't the application page showing that image? The thing is the image showing on the application page is not in my media library. I had deleted it.

I tried to remove the feature image from the wine post and saw that the other image disappeared from the applications page.
I then re-uploaded the feature image, but the image on the application page came back not the featured image of my wine post. I can't figure out how to fix this.