1st order is getting generated by 100 KM. While doing Preventive Maintenance, vehicle will not have any movements so that counter reading at the completion should as same as 100 KM.
I am not clear how & why you entered 200 KM for completion of PM order.
Also, if you complete the 1st Preventive Maintenance at 200 KM, from there only system should calculate the next order. Its not Time based as this will come automatically with predefined frequency. Your plan is Performance based & system will act according to the completion of previous Preventive Maintenance.
I don't find any reason to change behavior which is correct. I am not convinced with the development which is giving wrong details to the business.