Right Side Joycon could'nt connect wirelessly

Hello good people.

Nintendo Switch Joycon problem here.

This is a problem I’ve been having for a while. When attached, the joycons work fine. However, when detached, the left joy-con works fine, but the right joycon refuses to. It flashes it’s lights for a long time, and then never connects. What can I do to fix this?

Tried connecting using Pairing mode also fruitless. Left joycon detects and connect effortlessly to switch or to phone in pairing mode.

Reseat the antenna, tried with different know good antenna. Still doesn’t work.