I have net gear one, seems ok. They can sometimes just lose the network and need turning off and on again.
It needs to be placed somewhere between your router and the receiving computer, so check with a laptop or tablet or phone where the signal drops off and check for available sockets.
Or.
If your router and your son’s bedroom are on the same ring circuit and he wants/needs low ping etc. you could try one of these. I’ve got them rigged up to my desktop and the speed is really good, plus you can still use the socket. Need a free ethernet port on the router and on the receiving device though. That model is only good for one receiving device, i think you can get ones with more ethernet sockets though.