Image Optimization not Including Thumbnails Anymore

Hi. We have noticed that at some point recently, Litespeed stopped optimizing and returning all thumbnail images that WordPress auto-creates when uploading a media item. We only get the full size original as an optimized WebP and a related ‘.bk’ backup file. None of the 6 thumbnail versions our site generates are being returned anymore as WebPs. Up until recent uploads as of about a month ago (we rarely update this site), we would always receive the WebP, and often related .bk, versions, of all 6 thumbnail images along with the full size original.

While some plugins may have auto-updated, including Litespeed Cache (now at v7.9.1), WordPress itself wasn’t updated during this time. We don’t have any other caching or image optimization plugins on this site, it is pretty lean. The only thing we did recently was create a clone of the site, using WP Toolkit in cPanel, to create a staging site where we could perform updates and revisions to the site safely. On this staging site we did update WordPress and any other outdated plugins, along with shifting from PHP v8.3 to v8.4. I believe we had to relink this to our QUIC.cloud account originally. And it was on this staging site where we first noticed the issues. But the issue is happening on both the original live site and the staging site now. Both the live and staging sites show up as domains in the QUIC.cloud interface, with a status of ‘OK’. And both do show any image we’ve recently added in the ‘Last Optimized Images’ section, but only a single file (unsure if I should see the whole set of thumbnails there).

I’ve ensured our Image Optimization settings haven’t changed, which does have all thumbnail sizes checked to be included, along with the img.srcset attribute. And I tried disconnecting and reconnecting to QUIC.cloud.

Let us know what might be causing this and what might be helpful to try. We have reached out to QUIC.cloud support as well.