Add Static Mesh Component does not work properly (Multicast Event, 2Different Blueprints)

Hi.
I’m using UE 4.11.2 and have a problem with my building system when i try it on multiple clients. I have a “Player”-blueprint and a “BuildingSystem”-blueprint. The player one controls a kind of “Ghost Mesh”, which shows the player where the mesh can be placed (only clientside). When a player right clicks it fires an event to spawn a blueprint (Foundation/BuildingSystem) (RunOnServer->Multicast). Up to this point everything works fine, but when a player selects something else (like a wall), the object is sometimes not beeing placed (maybe cause the player don’t places a BP, it tells the BP to do so). After some tests i noticed that if I place an object (not the Foundation) in a special angle it will be placed (different every time, but if i figured out one angle, i can place every other wall from the same angle). I don’t know what to do, cause sometime it works and sometimes not.
I hope you can help me fixing this issue. Thanks.

Events:

BuildingSystem Event Graph:

PS: Sorry for my more or less bad Englisch, I’m not a native speaker.