Regarding arrTime calculation and how is it compatible with the vehicles setEarliestStart and setlatestArrival

Hello I’m working on jsprit for a week and I have a use case which is confusing me.I put the current time as EarliestStart on each vehicle whenever I hit jsprit because I have a minimum time delivery mechanism to the customers otherwise the delivery is free. So If I put the endTime of a task which the driver will take 20 mins to reach as just 5 mins ahead of its EarliestStart. Jspirt allots the service to the driver which is wrong ? Please guide a bit if I’m missing something here. I can provide the exact use-cases if required. Also I’m not able to understand how does it calculate the arrTime of each activity keeping in mind the time taken to reach previous activity to the new activity?