anna123ca

Great, thanks a lot! That did help.

Then what would be a proper way to hide those pre-loading boxes / image placeholders? I would like to make them invisible or all white to have them blend with the white background.

I think I forgot to mention. I see the issue when testing on all 3 devices: 4k laptop screen, and high res phone and tablet.

ok, I’ve created a temporary page with a gallery set up so that the thumbs are blurred after reloading from the cache: https://goo.gl/sSkmQN

and this is the good one with the thumbs forced to be the originals: https://goo.gl/wXqckC

Hi, thanks for your reply.
Well, I have a workaround as I wrote, and don’t want to reconfigure it back to the faulty version.

What I noticed with my screen and all the settings, is that it is only the 1st time when the gallery is displayed (after clearing the thumbs cache) the thumb images are crisp and high quality. And on this 1st time, the actual image returned from the server (if I save it from the browser) is 3x the configured size of the thumbnail on each side. All subsequent page reloads and navigating website links back and forth brings up a slightly (but noticeably) blurred view, with the thumb image size equal to my size settings (again if I save it from the browser). And once I clear the thumb cache in WordPress, the next 1st refresh of the gallery page brings up the crisp good images again. And all subsequent reloads are blurry again until the cache is cleared, etc.

So I presume that is not the browser or not only the browser that causes the blurred thumbs. The very first rendering of the gallery when the cache is empty, the images returned to the browser are higher resolution.
Why would it not return same image size/resolution on a reload unless I have cleared the thumbs cache on the server before doing the reload?