So, to simply put it, I’ve successfully managed to make a Leonardo (sender) and an Uno R3 (receiver) communicate using 2 nRF24L01 modules and the RF24 library.
The Leonardo sends data, the Uno receives it, I can work with data from both sides without a problem, perfect! 
At least while I keep the USB connection active after uploading the sender sketch…
If I disconnect the Leonardo and then reconnect it, the Uno receives no more data…
After the disconnect-reconnect routine, the “L” led gets stuck, no blinking of any other status leds. Upon resetting with the board’s button, the “L” led flashes, and right after it the “RX” led, and after stabilizing, still no communication whatsoever… :?
I have no idea why, to be honest, and was hoping anyone someone would be able to shed some light over this matter, as I’m struggling to finish an important project and it is vital that the system works on its own, without being connected to a computer… 