I think we may need the AI team to weigh in on this one and break the deadlock. 
The idea that there’s something ‘meta’ about the subcategories that the AI bot is just not picking up on is very appealing to me (based on the time I sunk in trying to do it via prompt ). Unfortunately I’m at the 
end of the AI spectrum so I have no idea if this is a reasonable assumption. 
However I did spot this post from Don that says the workaround proved successful for him: