So sorry for the cross-posting and for this shout for help that some can
read as a forum shopping, but this is really annoying.
https://bugzilla.wikimedia.org/show_bug.cgi?id=64622
In short, we on all Wikisource wikis are unable to start working on new
pages from digitized books (or for newly overwritten uploads) without
poking the server N times in order to generate a single resized image.
Please fix it ASAP. Please see also #c18 on the mentioned bug.