Problem: There’s some problem with Customer Order, we have already made partial invoice from this customer order and now we are making again the remaining invoice but when we generate invoice it shows full details not the remaining.
Solution: We have Customer Order including 3 items:
We already Posted posted one invoice for 2 items: 
But while generating the 2nd invoice for the remaining item , the system is including all items in a new invoice not only the remaining item:
The issue is caused by the date of the 1st invoice, it is preceding the 2nd invoice. In the above example, 1st invoice is posted on 05/12/2022, but 2nd invoice is created on 04/12/2022 (as per the system no sales were made before this date, therefore it 2nd invoice is not considered).
But if you create invoices subsequently, the system will show you only the remaining items and qty that have not been invoiced yet based on this particular Customer Order: 
Thanks for being a FIRST BIT Customer!
# partial invoice customer order based