Featured Image block in Query Loop loads too small (-142×88)

Hi,

I’m using the ONA theme and noticed that the Featured Image block inside the Query Loop loads a very small version of the image (e.g., -142x88.jpg).

This results in blurry, low-quality thumbnails.

Interestingly, in the Gutenberg editor, the image appears sharp and high-quality — but once the page is previewed or published, WordPress loads the miniature version instead.

I understand that the default Featured Image block in Gutenberg doesn’t offer an option to choose image size, but maybe the ONA theme could improve this by:

• Setting a better default image size (e.g., large or full) in the Query Loop context,
• Adjusting the sizes attribute to better match the layout,
• Or extending the block to allow choosing image size in the sidebar.

Right now, the only way to fix this is using custom JavaScript to replace the image source with the full-size version, which isn’t ideal for less technical users.

Any ideas?

Thank you,
Tomasz