Image url inside content has wrong size

Hello,
I’m using WordPress inside of a PHP application through the Rest API.
Everything works fine, except that in some posts attached media are not loaded correctly.

In the page I linked, the code generated for the image inside the post has this url: >http://newblog.photocircle.net/wp-content/uploads/2012/01/Fernsehturm-mit-Kulturlogenplakat_Foto-Arndt-Beck-682×1024.jpg

Originally I thought it was a problem of missing thumbnail sizes, so I used wp-cli to regenerate all the thumbnails. One of the sizes I have in the media settings is 1024×1024, which is the one I’m interested in in this case. The thumbnail it creates is this one: Fernsehturm-mit-Kulturlogenplakat_Foto-Arndt-Beck-683×1024.jpg

If you pay attention to the last part, it’s 683x1024, while in the html is 682x1024.
How can this 1px discrepancy happen? Is there a way I can fix this?

Thank you

• This topic was modified 1 day, 16 hours ago by Qarlo.
• This topic was modified 1 day, 16 hours ago by Jan Dembowski.

The page I need help with: [log in to see the link]