Regression on scheduled invoice entry grid - Sage X3 Sales Order

When we delete then add lines in the scheduled invoice grid, the total percentage calculated is wrong and an unexpected error message is displayed.

Reminder : this screen is accessible from the sales order, by right clicking on the lines (only for service or generic products which are not deliverable).

This bug appears in V11 Patch 17, it is fixed in V11 Patch 18 by maintenance 7656 (available on request), this maintenance can be installed in a V11 Patch 17 folder