Problem:
View filter not working for related fields
Solution:
Sorting view results with fields of parent post is not supported yet.
This feature is known to us and we do have internal ticket and I raised your voice to our internal ticket but I do not have any ETA when this feature will be added. Please note that there is no ETA on it.
Problem:
how to exclude specific taxonomy term from search result
Solution:
If you do not added category search filter, you will just require to add the taxonomy filter and select the option "NOT one of the following" and select the category you want to exclude from search.