The stateflow chart (and as a result, the subchart) will execute at every time step. If the time step is less than 0.2 sec, and if the subchart is active, then it will be checked at every time step instead of when "after" is true. You need to transition out of the chart if you want the "after" command to take precedence. Consider the chart below:
Assuming the time step to be 0.1, The simulink engine enters the subchart at time 0, but transitions to the "state that does nothing" at time 0.1. So, if you want the subchart to be checked every 0.2 seconds, you need to change the transition from the state to the subchart to transition after 0.1 sec (instead of 0.2).
Hope this helps !
