featured content size

Starting over, since I still don't have resolution for this. I m trying to get the featured content on my home page at https://explorationvacation.net/ to use a thumbnail of my featured image instead of the stupidly cropped size that is the theme default. You gave me some code, but it doesn't work all the time. I absolutely cannot figure out why it works sometimes and why it does not and I am really sick of it not working. All I want is to use the 200x200 thumbnail, but it sometimes insists on using the default size. This is on my homepage and it looks like crap. Cindy