Chosen Solution
No Joycon will connect to the left side of my Switch while in handheld mode. However, my Joycon must be connecting to some degree in order to charge while in dock. Could someone please help me to understand why my Joycon will not register in handheld mode, but has no problem charging? Thanks.
Try cleaning the bottom of the joycon rail on your switch with a toothbrush and isopropyl alcohol. Sometimes dust or hair or lint gets in there and covers the contacts at the bottom.
