I had problems with 2 sets of joy cons on my Switch (the usual left joy con issue), both of which were sent to Nintendo and repaired.
Once I got them back I noticed that the right joy cons had laggy or dropped inputs if I held the joy con in the wrong way (too much of my hand wrapped around it), had the joy cons too close together, or if it was too close to my body or obstructed by my leg. I probably didn't notice this before because of how bad the left joy cons were with their disconnects.
I sent everything (4x joy cons and the Switch) to Nintendo for repair but they said there was no fault found and that everything was operating within normal parameters.
Once Nintendo released the save data transfer utility I bought a new Switch and transferred all my data across. On this new Switch every singly joy con (all 6 of them!) worked perfectly, and on my old Switch all of the right joy cons had the lag/dropped input problem.
I can now use any joy con from around 6 meters behind my back with no problems even with 8 joy cons connected to my Switch simultaneously.
In summary if your right joy con appears faulty it's probably actually your Switch that's faulty and Nintendo may not repair it. I recommend buying a new Switch, transferring your data, and then returning your old one for a refund.