Half my pictures (featured images) don't work

I am having a problem with my images. Half the time they work, sometimes the featured images show and the blog post images don’t then when you try and change the blog post images they work and the featured images don’t work.

For example, one featured image is pointing to: https://wp-content/uploads/house-31926_200x200.jpg

I’ve tried going to settings>media and directing them specifically to wp-content/uploads
AND
https://domain.com/wp-content/uploads

But, alas, they are still not working!

Any suggestions?