[Theme: Hatch] Displaying Portrait Oriented images uncropped

I am trying to create a blog to post portrait images. Hatch almost does what I need, but I need thumbnails to display with the correct proportions and without cropping. Also, if I don’t use featured images, I need the blank space created by the featured image to not display.

You can see the site here:

https://momphoto.com/1000faces/

I tried working with a child theme from this post but I couldn’t get it any change to my images – they remain cropped and I desperately want them to appear in portrait orientation.

I also tried adding this to Appearance > Theme Settings > Custom CSS:

.home .hentry, .archive .hentry {height: auto;}

But it strangely only affected the thumbnail for a single post

Thus far I have:
A: Deleted and removed my featured images to get a fresh one uncropped one after installing the child theme.

B: Installed a fresh copy of the theme in case I somehow made some change.

C: Installed a fresh copy of WordPress in case that might do something.

Please help!