we have an idea that we need to deliver an order in package, the scenario is in order to do this we create a main end product [finished goods] and connected are often 2 sub production parts. We keep them scheduled together using pegged supply.

Scheduling backward from promised delivery date using synchronize works fine. But if we try to re-schedule the sub-production parts earlier to optimize production capacity when there is a capacity space earlier -> scheduling with references synchronized to main-prod order goes wrong for one of sub-prod parts. We need to keep full (sub)prod orders together as it needs to be sent to customer as a whole package.  

so if you re-schedule the jobs from the dispatching resource and set the scheduling date "forward from delivery date", it generates the scheduling job "forward from today", not the expected results.

Re-schedule 2 connected sub-production order parts forward from date earlier than originally planned & synchronize scheduling to main-prod order is causing that first sub-prod order is scheduled forward today instead of entered 'scheduling date'. We need to schedule full order and not only one job to keep operations of sub and main prod order aligned in the factory. There should not be to many gaps in production planning dates because of WIP space/overview problems & production lead times are short.

the problem is impacting the business as Efficiency in scheduling and use of available capacity cannot be improved, and incorrect planned dates create issues in keeping connected parts together. This results in an inability to deliver the full package to the customer on time and causes unwanted work-in-progress (WIP) and space problems in the factory due to misaligned scheduling.

Planners manually attempt to keep the main production order synchronized, requiring extra effort, and reschedule without using reference synchronization settings.