shipment completion tab is not getting selected in VT02N

HI

i have an issue with a s cenerio

we have done PO then we hve done outbound delivery wrt PO but when we do shipment ,in that we have selectd check in and planning tabs

but issue is we are not able to select shipment completion tab , as we save it

it remins unseleted

as we do it it would be posting a GI

it is nit getting selected

earlier we have selected shipment start/end and then shipment completion

when we save it only shipment start / end buttons are remaining selected ..

shipment completion button remaining unselected

Awarded suitable points for right answer

warm regards

adarsh