Ah. When you go to the form UI setup, it still shows as the old name?
This is because there are two names for a taxonomy. The name, which you have changed, and the slug name, which cannot be changed. For example, when you try in CPT UI (a taxonomy plugin) to change the slug of a taxonomy, it warns you that doing so will actually create a new taxonomy, and asks you if you want to transfer the terms over?
Doing this WOULD let S&F see them. So, instead of renaming the category thing, use CPT UI to make a completely new one with the correct slug, and then use the Taxonomy Switcher plugin to move the terms over.