Search Events Module (mod eb_search) with Category id - No results

In our organisation we have events that are bookable and non bookable. All the events both bookable and non-bookable are in EB. For the non-bookable we disable registration.
We have a page of upcoming (boobable)  events for our Season's events. As we have a lot of events during the season we want to allow people search by date
To limit the search we have a category called Bookable Events and then under that children categories of bookable events (See screen shot). Non bookable events are not under the Bookable Events category.
In the search module we specify id of the Bookable Category.
We put the search module on the same page as the list of upcoming events (see screen shot) so that people can search for bookable events based on Date
But when we run the search it produces no results. So it looks like the search only looks in the Bookable Category and not its child categories
If you don't put a category id in the search displays results from every category (for us this includes non-bookable events) which we don't want to display.
Also you can't enter multiple category id's just to search on categories your want to search.
Is there a way around this?