@Gabriel2Silva were you able to solve your problem? I'm currently facing the same issue with my right Joy-Con. Did yours also give up connecting after one cycle of the LEDs? Mine only tries to connect for an appropriate amount of time (cyling through the LEDs multiple times) if I long-press the...
Serial: XAJ40045004946
Serial on device matches serial on box: yes
Region: EUR
Firmware: 4.1.0
Color option: Gray
Store: Medimax
Was a bundle (if yes, which): no
Purchase date: 30th April 2019
Fusée Gelée works: yes