Turning the lights back on was not as straightforward as it seemed, mainly because every formation Lex had ever interacted with before this was generated by his system. As such, the formations would directly act according to his intentions and Lex did not need to bother with the details of how the formation actually performed the relevant action. Now, on the other hand, there were hundreds of options for Lex to interact with and he could not easily figure out what they did.
A simple example of this is taking an avian beast that's been flying all its life with the aid of its wings, with each and every manoeuvre easily performed at a whim, and putting it in the pilot seat of a commercial airline. It could not even begin to comprehend what the various buttons did.