@HW1
I was able to replicate your situation.
The macro category will not appear if there is no macros existing in the search folder.
In order for the Macro Category to be appear, it requires there are some macros present in the target folder.
The macros are there in the respective folder.
However, upgrading Alteryx from 2020 to 2021 helped.
I guess, it was a version issue.