Why does Hikaru Nakamura avoid Carlsen? I like watching Hikaru's youtube videos. 

His commentary on the games is very descriptive, unlike other players that stay quiet for most of the game. Hikaru's always talking, letting you know what's going on.

However, one strange thing I've noticed is the COMPLETE absence of any sort of online interaction with Magnus. He's uploaded hundreds of videos, yet none contain matches against Carlsen. 

I thought this was strange, since I know Carlsen plays a lot online too, and Hikaru's got matches with a lot of other top players, but never Carlsen.

The other day, I noticed a youtube comment in his video that said "play Carlsen", and somebody responded with "we don't mention that name here", and it got tons of upvotes.

So I am clearly out of the loop here: what's going on? Why is Hikaru actively (seemingly) avoiding Carlen online?
There was there match in the 2017 chess.com speed chess championship final, but I think that it has to do with Carlsen mainly playing on chess24 and lichess while Hikaru plays on chess.com(mainly). This is not to say that Hikaru tries to avoid playing Carlsen in general as they both had huge fighting games together. An example I can give is their game from the London Chess Classics 2017.