That is what the modules does but just when the shipment is created.
If you have several shipments created before the grouping is set to Standard (or even the module is activated) you must manually remove the existing system.
This will automatically reprocess the sales and create new ones grouped.
set them to today’s date if you want them to be grouped into a new shipment
create a new sale & shipment
deliver
Steps 1 and 2 can be automated:
Goto menu > Administration > Scheduler > Actions
choose ‘Reschedule Customer Shipments’ and set the interval of your choice. Then all waiting shipments are re-planned for today’s day.
There is a schedule dtask you can create that will plan all past shipments to today.
So there is no need to do that manually. You just need to create such scheduled task and decide at which time it should be executed.