I am developing a couple of sites in 8.21. When I upload multiple images, and say, place one on a page, then go back to place another image, the newly uploaded images are not listed. So I click the trusty arrow to reverse the "Date Modified", then click it again to get the most recent view again (watching that blue line snake across the window...) and voilà, there they are! If I click on "Files" in right hand popout drawer thingy (let me know if I am getting too technical), the files are listed as they should be. Go back and place images from a page, and they disappear again until flipping the arrow twice again.

I do not have any caching addons, no memcache or varnish on the server. Caching is turned off. I clear my cache regularly. (I am very cache-conscious...) Yet the behavior persists. I have other funky cache gremlins during edit sessions. Even a simple edit of a content box (with no images) will sometimes disappear. Or adding images to a slide show—even before clicking the ole Publish button—some images disappear from the little thumbnail preview box. This behavior is occurring with different themes. I want to migrate all my older sites to 8.21, 'cause Franz said I should, and there is no doubt that he is waaaay smarter than I am about this stuff. But I am a wee bit vexed. Is there something obvious that I am missing? (Wouldn't be the first time.)