Hi,
check this
It could be a case sensitivity thing with chrome, who sees jpg and JPG as two different files. The warehouse in sketchup uses chromium, and you use chrome.
No idea why chromium does that in 2023 still, when al the other browsers I tried were fine with case sensitivity. Case sensitivity stopped being an actual issue what, a decade ago ? two ? but not for chrome I guess.
Simply renaming the files in lowercase should do the trick. no idea why some softwares still export files with an uppercase extension anyway.