Hi @rdbrid,
@braktar is right that you should not use .setArrTime() and .setEndTime() in your constraint. We had a related discussion earlier in this post.
I think you have calculated the arrival time and end time of the activities correcly by arrTimeAtNewAct and endTimeAtNewAct. You just don’t need to call .setArrTime() and .setEndTime() to set new calculated times.
Best regards,
He