Single post image size

Hi, I am using the Hatch theme and have created three new posts with a featured image, however the images are being cropped instead of showing the whole image.

You can see here how the image is being cropped: https://www.artstreamalbury.com/judy-watson-pituri-vessels/

And this is an older post where the image isn’t being cropped so this is how it should look: https://www.artstreamalbury.com/susie-losch-no-1-red-crane/

I tried changing the Medium size Maximum height to 600px under Settings/Media but that didn’t make any difference.

Can you please tell me what the issue would be?

Thanks, Carley.