AttachToActor and SetActorRelativeTransform replication not working reliable

Hi folks,

i am currently running into an issue with attaching an actor to another one and afterwards settings its relative transform.
I am spawning those elements in the BeginPlay of the current GameMode, so its spawned on the server.

First, i am creating the parent node, then attach 100 children to it.

It works, when spawning the “dummy” actor (which has only a static mesh as child - thats it). But as soon as i’m using a more complexe Actor with more properties to be replicated, it seems that the network traffic gets way too high, and not all attachments are replicated. When i’m running the game multiple times, the amount of attached children is always different - sometimes there are 30 attached and 70 not, sometimes about 50 / 50…

Can i somewhere set a flag that the attachment has to be reliable transferred to all clients ?

The next issue starts that the relative transform is not properly applies. E.g. my Parent has Coordinates 10 / 20 / 30 and a rotation of 40 / 50 / 60 - the children’s relative transform is the same, ignoring any transforms i set to the the SetActorRelativeTransform. Any clues how to force a proper relative Transform? I also logged the transforms on each participant - server’s transform is correct, client’s are completely out of bounds.