I have Pokemon Shield and I'm trying to evolve my Inkay.
I went into my Bag, turned the console upside down(I was playing handheld), and fed my Inkay a Rare Candy, leveling it up to 30.
Why didn't it evolve?
You have to turn it upside down before it levels up until it evolves. So turn the switch upside down, THEN feed it the rare candy.