Can't cast commander after restarting game with Karn

In a commander game that has been reset with Karn Liberated's {-14} ability, you can't cast your commander from the command zone.

It doesn't seem to matter whether or not you've cast your commander in the original game.

**Relevant rulings:**
> In a Commander game, each player puts their commander into the command zone before shuffling their deck, unless it was exiled with Karn. In that case, the commander remains in exile and will be put onto the battlefield when Karn's ability finishes resolving.
(2020-08-07)

>The number of times a player has cast their commander from the command zone resets to zero. The amount of combat damage dealt to players by each commander is reset to 0.
(2020-08-07)