It's hard to say without seeing the project. But some general tips:
Unity does not guarantee any particular execution order of monobehaviours. PlayMakerFSMs are monobehaviours, so in any given update, you cannot rely on them being executed in a particular order.
Maybe your FSMs are running in a different order than you're expecting? If you need to enforce a particular order, use events. E.g., when FSM 1 has done its step, send an event to FSM 2 to do its step...
Also, try looking in the FSM Log to debug execution order. You should be able to follow state changes and events. E.g, click the event that caused a state change to go to the FSM that sent the event; Or pause the game then click back in the log, now you can select other FSMs and see their state at that time (indicated by the yellow bar).