Hey Michael,
To mimic the design of the archive page, I have made the changes to your website.
In your post element, I change the padding from 1 to 0.
In your figure, I change the min width to 0, max width to none, height to auto, min height to 0 and max height to none.
In your image element, I change the object fit to cover and set the height to auto.
and add padding to your title and excerpt. As you can see the featured image is now working properly on the frontend.
You can now replicate the same steps to your column 2 and column 3.
Hope that helps.