Hi Laura Bookman,
Thanks for the post. I gave this a quick test with an image referenced via URL in Chrome 86.0.4240.75 and was not able to reproduce the issue. Would you be able to share your web map with PeterK_ess so I can take a closer look?
The image is a URL that isn't https. and it is all images that aren't displaying. I can't message you privately to send the site since we aren't friends / Connections.