Following PID:266394 I investigated if the last invoiced field is populated with the Unleashed integration. JJ looked in the code and confirmed it does not get populated. I looked at the customers end point in Unleashed could not see any fields which correlate with the last invoiced field on Sledgers in Prospect. But if there is a field which matches we should populate it.
This need implicated to be for all account system
Customers have pointed out this as being completed date on unleashed sales trans but we should check this in house regardless