Prevent Image Resizing

Hello,

I’ve googled and searched through the forum and I can’t find any way to resolve this issue.

On this page:

https://IndieHorror.org/convention-floor/

I absolutely need that image to be 650px wide. For some reason it is still scaling the image down.

Things I’ve tried:
-Adding the global content_width to functions.php and setting it to 650.
-Changing all occurrences of a lower content width in style.css to 650.
-Fiddling with width and height values in the image tag.
-Adding size-full to image style.

And probably several other things over the past two hours.

I would greatly appreciate any ideas on how to fix this.

Thank you,
Matthew