Featured Image Showing Last?

Hi there!

I am having trouble with my featured images. Some work, but others are being pulled from within the my posts. When this happens my “set” featured image appears last in the thumbnail line. I have tried adding featured image plugins and reposted several articles to no avail.

I have linked the problem here: Lifestyle Development Matrix
You can see that two of my featured images are showing properly. However, “What are the best pre-workout supplements” is pulling an image from within the article.

Any assistance would be greatly appreciated.
All the best,
Zachary Williams