Bex Query - 'Characteristic Restrictions' problems since we upgraded to 7.40

In the Bex Query, ALL of our Characteristic Restrictions are losing the full list of values once a subset has been selected.

Example - 0ASSET_CLAS

The dropdown initially shows  multiple Asset Classes.  We then select Class 1, 2 and 3, then go back into the dropdown list and now ONLY

classes 1, 2 and 3 are available - ALL of the Asset Classes are no longer available for selection.

IF we exit the query and re-enter, ALL of the values reappear.  If we CLEAR the Characteristics Restriction, run the query, then go back to the dropwon, ALL of the values appear.

I have attached two jpegs which depict the issue.

Any help appreciated.

Regards,

Gerry Steer