Why can't I sort in Writer? [Solved]

Because in my 200 page doc I inserted by accident, weeks ago, a graphic 1 pixel in size and invisible to the Navigator.

. It’s the apparent fly-speck to the left of the word Tuhianga. It’s anchored to the page, so it seemed to jump from para to para.

Solution below.
More puzzlement: (1) is there a bug, that Navigator doesn’t show the graphic?
(2) Why shouldn’t LO sort text around it?

LO on OS X 10.6.8

By identifying each tranche that does sort, isolate the para that does not sort. Display at 400x and get lucky. Select graphic. Only when you do this will the anchor appear. Delete graphic. Sort file.

Yes. For tiny graphics you basically have to zoom fully in (600%) to have any chance of selecting them. Not all objects show in the Navigator. For example, I have seen it have problems with custom styles. In Writer graphics do not have styles, but it may have been a related problem.

Good point – 400 (etc.) per cent display is not 400x; it’s only 4x. And I call myself a maths teacher!