If you are not aware of the little problem of the Joy-Cons, the main controllers of Nintendo Switch, here's a little summary: due to some flaws in the design, the Joy-Cons had several problems launching the console - due to some connection problems Bluetooth - and during the entire life of the system, due to the drifting analog sticks.
“We apologize for any inconvenience caused to our customers regarding Joy-Con. We are continuing to improve our products, but at the moment Joy-Cons are part of a class-action in the United States and it is a problem that we cannot talk about in depth. "
In short, almost halfway through the life cycle of the console, Nintendo has finally formalized the problem. Furthermore, should you encounter this problem, you can safely request a repair of your Joy-Con through the Consumer Service of Nintendo.