Symptoms
Filter doesn't work correctly when using input mappings on user field
Diagnoses
I have a list that uses a Person type to capture the identity of a user. However, when I try to filter the list in a list view using input mappings to only show items for a specific user, the list is returned empty. When I add a filter, it works, but if the list of items to be filtered is large, performance will be horrible.
Resolution
The issue you have found has been successfully reproduced and has been logged as a bug. Since this has been logged as a bug the issue should be fixed in a future release of K2 Appit for SharePoint.