After buying, the download image is only a thumbnail

Hi, I just installed the Image Store on my website.

Almost everything is working ok. I can publish, buy, paypal is working fine, both seller and buyer get their emails, and I’m redirected the “receipt” page with a link to the file download.

The only problem is that this download link is for a 380 px wide picture. This is the default value of the thumbnail.

I made sure I selected 1920 px on the ‘Pricing’ list.

I tested checking ‘link to attachment’ on the gallery edit page but the link on the post itself says ‘Published at 1920 × 1280’, pointing to the 380 px file.

Is it a limitation or am I doing something wrong?

Thanks!