I’ve seen this one several sites.
The category description is displayed on the category page only if there is a category image.
Edits to the category description topic show up in the topic and even in the json for the category, but not in the category display.
When I have edited from A to B to C I have seen B get displayed after some period of time, edit the text to C and then see text A again on reload.
This seems like a bug but I can’t figure out just what it is.