I have seen some ask about this a few times now. From the replies I'm not sure if the problem is understood.
When Activity 1 is active that have Device 1 and Device 2. If Activity 2 is called with Device 1 and Device 3. The Activity 1 "Shut down" command for Device 1 should be ignored along with the "Power on" command for Device 1 in Activity 2.
If we have any SW developers that look at these forum posts, do you know if the power state is stored? If so, can that state be checked before calling either the (Power on) or (Shut down) command for a device in an activity?