Split screen wasn't even available during the entire early access period
Yeah, I bought the game expecting split screen to be as good as Divinity OS 1 and 2. Honestly at this point I regret the purchase. It's still a fantastic game, but I have other games I play single player, or online. We wanted an experience we could play together, spending hours sat on the sofa having a shared experience, and currently this game isn't it.
My own fault for breaking my 'never pre-order a game' rule.