Joy Cons that came with the Switch do not register button presses and they slip off the console without lock disengage button. New Neon Blue Joy Cons have a disconnection issue with the right Joy Con. Worst controller that has ever been made.
Edit: Break them in. The stock joy cons needed to push the button harder to register input... still slips out of the rail and that sucks. The neon blue joycons disconnection issue is gone. Maybe firmware updates? Updated review to accurately report on product.