DataGrid Loaddata Args

I´m implementing LoadData event for DataGrid using EF.
while debugging in our demo project (assembly version 2.10.14) the filter value is "contains(LastName, 'd')"
in my project (assembly version 2.10.15) the filter value is "((CustName == null ? "" : CustName) == null ? "" : (CustName == null ? "" : CustName)).ToLower().Contains("s".ToLower())"

My preferred way would be to be able to use this filter til build query on dbcontext without OData service.
Can you guide my in wright direction.

The filter value depends on if the DataGrid is bound to IQueryable or ODataEnumerable<T>.