I have some CSS like this:
background-image: url('/img/high/logo.png'),url('/img/low/logo.png');
Intermittently, on Firefox on PC for sure, the image doesn't display. My debugging has led me to believe that the issue happens when the high resolution version of the image comes back with a 304 Not Modified response (which happens intermittently I guess, or the browser cache doesn't have the file intermittently, I don't know which). I was lucky enough to notice it on a slow computer when the low resolution image (I think) flashed on screen for a second before disappearing.
How do I stop this from happening? The images are being served via cloudflare (free tier) if that makes a difference.
