SUB AND GRAND TOTAL ERRORS

Reformated DAX for the comfort of any reader of this post:

=
IF (
    COUNTROWS (
        FILTER (
            'Order Booking - Improved New',
            CONTAINSSTRING (
                'Order Booking - Improved New'[Collection],
                "NOS"
            )
        )
    ) > 0.,
    SUMX (
        'Order Booking - Improved New',
        ( 'Order Booking - Improved New'[ORD ON HAND] * 0.03 )
    ),
    SUMX (
        'Order Booking - Improved New',
        ( 'Order Booking - Improved New'[ORD ON HAND] * 0.05 )
    )
)

KAYKAY181159 
What you want to do?

What was the error?

In addition if possible share sample data.

KAYKAY181159 First, please vote for this idea: https://ideas.powerbi.com/ideas/idea/?ideaid=082203f1-594f-4ba7-ac87-bb91096c742e

This looks like a measure totals problem. Very common. See my post about it here: https://community.powerbi.com/t5/DAX-Commands-and-Tips/Dealing-with-Measure-Totals/td-p/63376

Also, this Quick Measure, Measure Totals, The Final Word should get you what you need:
https://community.powerbi.com/t5/Quick-Measures-Gallery/Measure-Totals-The-Final-Word/m-p/547907

Also: https://youtu.be/uXRriTN0cfY
And: https://youtu.be/n4TYhF2ARe8