I have noticed sometimes if the filename has a bunch of funky characters in it or if it's an animated GIF, it will not resize the image. Hope that helps!
{{ resize_image_url(content.post_list_summary_featured_image, 0, 0, 740) }} should be correct.
For a long time I didn't think this function was working, but what I noticed one day is it can take a couple of minutes before the new sized image is available, in which case it will return the full sized image until then - so no broken images while that occurs.
I have noticed sometimes if the filename has a bunch of funky characters in it or if it's an animated GIF, it will not resize the image. Hope that helps!