We are running Magento ver. 18.104.22.168 and have run into an issue I have not seen before.
We have two top level categories that you can grill down - Manufactures and Parts By Accessories
When in category view, ALL categories expand however, when we are in product view I can only expand Parts By Accessories.
Had a quick look on Google but no one seems to had had this?
Quick update on this:::
Yes I have reindexed etc ....
When I look at a product that already exists in the Manufacturers it's fine - Only appears to be happening for products NOT in this category and when I attempt to add new.