Pages won't change order in Pages

Neither Pages '09 v4.3, or any later version of the less featured Pages applications (after Fall 2013) will allow you to drag page thumbnails to rearrange them while enclosed in a section block. Now, you get to select the page that you want to move, cut it from the document, and then immediately insert it before the page where you want it moved too.

Only Apple could get away with this crude word processing nonsense. Non-Apple word processing applications are in full press competition with one another, and omitting a simple way to move pages around would lose customers.

I am critical of Apple where it gets things wrong or is muddled and inconsistent in their design (too often now unfortunately), but not in their insistence on preventing document scrambling.

Moving Sections by dragging makes sense because Sections have defined beginnings and ends and the content of the Section is one block of text. Pages however in Word Processing documents thread themselves across page boundaries and dragging their thumbnails around rapidly ties the text into knots. Something I experienced very early on in my DTP days when a client (actually two clients, issuing conflicting instructions) insisted I rearrange the pages in a long report, whereupon we soon could not untangle the loops of text flowing willy nilly back and forth.

IF your document has logical breaks based on pages, then either use a Layout template or add Section Breaks at the end of each page making each a Section. At which point I remind readers that Page Breaks are what they say they are and are NOT Section Breaks!

If it was a Layout document and you could not move the thumbnail, is it possible you were looking at the Master Page of that Layout? ...and when you reopened the document you were back to the normal page thumbnail?

Apple's chosen method for Master Pages is frankly extremely confusing for what should be straight forward.

You may want to look at alternative Apps. Swift Publisher is one and Affinity Publisher is currently in beta but looks like it will be extremely good once ready for prime time.

One can still be all Mac, and use the tools (Apple or otherwise) that lessen frustration, and improve productivity. Give or take a couple, I have used about 30 word-processing/DTP tools in my life, and Pages is not the pinnacle of that experience.