Cannot Filter Course Instructor name for particular "Course A"

Hi Anonymous 

please try

Instructor Name for MAT1 =

COALESCE (
MAXX (
FILTER ( 'Table', 'Table'[Completed Course] = "MAT1" ),
'Table'[Course Instructor Name]
),

"Test not found"

)

Thank you so much. Your solution worked. Really appreciate your time and consideration.