Nintendo Switch - Wifi issues & Joycon repair

2 questions:
1) The Joy cons on my sons Nintendo Switch have bad stick drift and the top right bumper button does not work.

I see from their website Nintendo offers free repair service. Anyone have experience with this? How long it normally takes? Is it just free repair on the stick drift or would they also fix the broken bumper button? Would love to have fixed for free than spend $80 on new ones.

2) The wifi signal goes out often on the Switch. Either a very weak signal or he loses connection while playing and gets kicked out of a game. I have AT&T fiber and no issues on any other device. He plays very close to the routers as well so its never an issue of being out of reach of the signal. Is this a common issue and any possible solutions?

Thanks for any advice.