I got it working! While one could go buying random Joy Con 2 grips until one worked, I just bit the bullet and bought the official Joy Con 2 Charge grip and it automatically registered.
What led me to trying this even though the Official grip is...
The tutorial still specifies using some grip (or a dedicated connection cable, whatever that is) to connect the joy cons to a computer. Unless I missed an instruction somewhere?
What design was your charging grip? Maybe there is a grip being sold that can connect the Joy Cons to a computer that we just got unlucky with obtaining?
I am in the same boat as you are. I have three different charge grips for my Joy Cons: 2 have a built in battery while one doesn't but neither of them get recognized on the program. Not even by holding down the analog stick or disconnecting and...