Goods issue date &1 &3 copied from schedule line: up to now &2 &4 planned

What causes this issue?

When creating the delivery the <DS:GLOS.goods_issue_date>goods issue
date</> is copied from the schedule lines already delivered. The
earliest goods issue date is copied into the header of the delivery. A
note informs the user of differing planned goods issue dates.
In this case the goods issue date of the delivered schedule line is
earlier than the goods issue date determined for this delivery for the
previously delivered schedule lines of the same or other sales orders.

Error message extract from SAP system. Copyright SAP SE.