A few things to try:
You don't need the for each loop, the game will trigger an event individually for each 'Spawn' if their bool is active.
There is another action that causes the actual object to spawn another object rather than the System. In the 'Action' menu click on your 'Spawn' and click 'Create another object'.
Additionally if this doesn't work for some reason, you could try the actual timer behavior. Add the 'Timer' behavior to your 'Spawn', set a Tag like 'spawnEnemy'.
When bool = active
AND
Timer 'spawnEnemy' is NOT running (right click and invert this condition)
Then Start Timer 'spawnEnemy' for X seconds.
On timer 'spawnEnemy'
Then the 'Spawn' creates object etc.