How do I fix this? It's a new Wireless Receiver.

I've tried updating the firmware, and it's now on V1.28.

I've disconnected all paired devices and hard rebooted the Switch. I've tried different USB ports too. I've even tried different controllers like my DualShock 4, but that doesn't even give me any response even if the Switch tells me it's paired.

On my PC, it just holds down the entire time with a random button every once in a while.

Same thing happened to me.

8bitdo offered to trade it out but I’d pay for shipping. Which is more than a new one is.

So it’s currently in a drawer until a firmware update fixes it.

It’s a shame since when it works it’s glorious.

EDIT: It also lets you wake up the switch with any remote with a home button.

I came here looking for help with a similar problem. My Wii U Pro controller previously worked on my Switch with the Retro Receiver, but since updating the RR to v1.28 (for Genesis Mini support), when the Wii U Pro controller pairs to it, the only inputs that work are the left stick, which seems to do random inputs or scroll downward in menus. (It still pairs and works perfectly with my NES Retro Receiver, and of course on the Wii U, so I know it isn't a problem with the controller.) I suspect to use that controller with the RR again, I will have to roll it back to a previous firmware unless 8Bitdo fixes the issue. I'm not sure which was the last version that worked though.