Part ship confirm----ALL transaction's SHIPPING_INSTRUCTIONS and PACKING_INSTRUCTIONS missed

Form:WSHFSTRX. , wsh transaction

Action:  Just Enter the   SHIPPING_INSTRUCTIONS and PACKING_INSTRUCTIONS info   at shipment level (no info at line level、header level);

Then  part   ship confirm  (ship confirm window select entered quantity ship   )

example : line two quantity ,ship confirm   just one ;

Que: After ship confirm  and SRS  request complete,  ALL transaction's   SHIPPING_INSTRUCTIONS and PACKING_INSTRUCTIONS   missed,inclue   already shipped confirm  line;

why? IS exist the system profile 、setup or another ;

thanks for answer;