Okay so I have done everything that you have stated to do, and I've been going back and forth with this for over an hour now. I get no errors, but instead it just doesn't work. I have both joycons connected, and ran everything. Everything is set up, but it still doesn't work.
I went to a garage sell last saturday, and the lady had a PS2 for sale, but she had a sign on it that said "Nintendo -$50", had to laugh, almost bought but she didn't know if worked, and she didn't have controller or cables, so I passed.