Hello @Richard-Keith,
I have the same problem for the images at my project page.
I checked the "lazy loading" and the "
Image Placeholder Background Color" in lay options and I added the code you said in my custom CSS area, but it doesn't alter the background-color when they're loading. Do you have any advice ?
Thank you in advance
(here's a link to my website, https://www.louiseterrasse.com/)