Interface Call doesn´t work sometimes

Hi everyone,
i´m making a rts game and i have the problem, that a interface call sometimes work, but sometimes not.
So i have a MainBuilding BP and a ResourceWorker BP.
When the ResourceWorker arrives at the MainBuilding he makes an Interface call.
The MainBuilding then add the Resource and the Worker gets destroyed.
This works really fine, but when multiple Workers arrive at the same time, it looks like the interface call doesn´t work sometimes.
So the Worker is still in front of the MainBuilding and no Resource was added at the MainBuilding.
Is there a Problem if to many interface calls are made at the same time?

Is there another way to make a communication between the two Blueprints?
I thought an interface call is a good idea, because every building-type reacts different to the worker.
For me its difficult to debug the Problem, because it works 98% of the time.
I hope somebody can help me.

Unreal Engine is 4.26.1