Did you lose your saves?
I'm worried my tablet is the culprit, actually. I've tried several different joy-cons and all of them start having issues if my legs blocks line of sight while sitting on the couch (about 8 feet away). My latest pair only does it under extreme circumstances though, and both pass the behind-the-back test (from about 12 feet away) with flying colours, so I'm not really sure what to think.
They transferred my settings and data to the new unit. Even the wifi password was already saved there.
Had to re download the eShop games though