The last time I tried to use my Switch, I realized that the joy cons are no longer usable separately. Seems the connection to the internal shoulder buttons is broken, and you can't reorient the controllers unless you can hold them both down.
I dropped my Switch from knee height, and now the left hand joycon is slightly loose and disconnects from too much upward pressure. Maybe the damage is on the joycon, but it seems more likely the mechanism (don't have a spare to test).