Hello,
You shoud never manipulate setArrTime and setEndTime.
As mentionned @Bhoumik_Shah, you could model the service time contraction as a delay to reach a new location directly in the time matrix.
I’ve worked on such feature and called it “SetupTime” which is equivalent to a preparation time once we arrive to a new location and seems to meet your requirement.
I’ve just updated it !
So you can define the setup time instead of service time in the problem definition