Filtering a view by a checkbox field
this is some sort of a bug / incosistency of how the boolean field is made. if you leave it in default, without any 0 / 1 values, it wont show them in places like this filter.
But : the values are there :) under "Select all" you have 2 rows that just dont have captions. When you pick one of them, you can see that the SQL for your view is changed.
The workaround would be to add some captions to the values in the field defintion.