I am not sure what is wrong, but right now the CDN does not seem to be relaying url parameters on images back to your WordPress installation. For instance a url like https://www.puppyimages.com/wp-content/uploads/2018/11/Im-thirsty.jpg?debug=true (note the “?debug=true” at the end of the url) should be producing some debugging text output, but it doesn’t.
Are you sure you have set the CDN option set to Standard and perhaps purge the CDN cache one last time just to make sure?
Other than that I am afraid that I cannot debug this issue any deeper from the outside. I would either need to have access to your website files or, alternatively, you could try and disable the CDN so that we can test things without it in the middle.
Cheers,
Takis