I think this is a bug impacting the OOTB grids as well, but basically when you search a view then apply a filter the text search seems to still be applied while the text is removed from the field.
So the repro steps are:
Add search text
Add filter and apply to return to the view
As you can see the search text has been removed and in this instance without the search text I would expect 5 records to be returned, but instead I see none as both the filter and search have been applied.
Is there a way I can handle this in my control to clear the search filter if a new filter has been applied?