Hi UC/All,
I don't know why, but my ImageDataObjectManager was behaving strangely whereby it would reverse the sort order of my Images when I either enable 'Allow drag & drop reordering' or move the image size slider.
I remedied this by passing 'ORDER BY SortOrder' as the $sourceSort parameter.
I'm sure I've never had to do this before though.
(I'm using the latest SilverStripe version in the 2.4 branch)