Hi,
Did you run this plugin?
https://wordpress.org/plugins/regenerate-thumbnails/
To regenerate the image?
Go to Tools -> Regen. Thumbnails
to regenerate the images?
https://wordpress.org/plugins/regenerate-thumbnails/screenshots/
Or disable plugins to find out which plugin is causing issue.
Another question, did you modify the image size in theme code?
By the way, I used your image on my localhost test site.
The is how it should look.
Thank you