Help with state machine diagram

Hello,

I have a doubt regarding state machine diagram in CSM. I send a signal through send signal action in a activity diagram. I want this signal to be received by state machine diagram and use it as a guard condition. When I simulate the state machine diagram separately, it works. But when I run the simulation of the whole system context. the signal is not getting consumed/ used for the guard of the state machine diagram. Could anyone help me with this.

Thanks in advance.