Macbook Air can't detect an external monitor if I plug in, unplug, and plug back in again

I have an external monitor I plug my macbook air into.

If I unplug my screen from my laptop to move around, and then come back and plug the screen in, the macbook does not recognise the screen and it will not work.

The only way for the screen to work is to turn my macbook off and on again with the screen plugged in.

I presume this could be changed in my setting but I can't find where it could be??

Any advise would be much appreciated!

Thanks!