Filtering Out Specific String in One Field Within an Average Measure That Uses a Relationship

I have a field called 'Loans'[DTI]

I want to calculate the Average of this field using the relationship 'Date'[Date], 'Loans'[Funded Date] while also filtering out any records that have the 'Loans'[Loan Program Name] field containing the string "ABCD"

Here is what I currently have and it's returning the error: "The True/False expression does not specify a column. Each True'False expressions used as a table filter expression mest refer to exactly one column."

AVG Funded DTI =
CALCULATE (
    FILTER (
        'Loans',
        NOT ( CONTAINSSTRING ( 'Loans'[Loan Program Name], "DSCR" ) )
    ),
    AVERAGE ( Loans[DTI] ),
    USERELATIONSHIP ( 'Date'[Date], Loans[Funded Date] )
) / 100

I'm just not familiar enough with DAX to know where to add the filter. any Help would be greatly appreciated!