MacBook pro - External screen flickering after reconect

I have MacBook Pro late 2011. When I am at home, I use it with my external monitor, when I connect external monitor for the first time (after reboot), everything works fine, but when I disconnect the external monitor and reconnect it again, the external monitor starts flickering and external monitor screen starts turning on and off. The MacBook's default screen works fine. If I reboot macbook and then connect monitor, everything works fine until I disconnect and reconnect it again, then it starts doing that weird things again.

I don't want to reboot my MacBook after every time I disconnect external monitor... I am thinking, maybe I am not disconnecting the external display right. I just disconnect the cable. Should i be doing it another way?

Does someone have some experiences with that? Could someone suggest me any solution?