Simulation: activity diagram is ran before the signal is received

Hi guys,

I am a bit new and now aware of the correct terminologies. So I have an IBD and in that I have multiple parts connected by proxy ports. Each part contains an activity diagram based on which we get the outputs from these parts.

My question is that I have noticed that when I run the simulation of IBD, then all activities diagrams are activated and simulated all together. I can be seen that output from one part1 is the input for part2. But if the activity diagram in part1 and part2 are ran together then part2 have not received all inputs yet and I get incorrect answer.

My goal is to somehow receive all inputs before running a activity diagram. What can I do?