how do I make it work?

I just want it to wait 2sec before it goes sleeping again ,but sometimes it just goes sleeping when the player (witch) is in line of sight and I don't know why

It is hard to understand what is happening when we do not see it in action. Please share .c3p file

The initial trigger of event is yet to finish (2 sec later) and once done it runs the rest of the action. That is why you are seeing instant sleeping animation which is from that initial trigger.

To continuously trigger this event, you need to add 1 more condition such as "enemy1 animation is wake"