Larian Studios Forums Divinity: Original Sin 2 - The Modding Dungeon Divinity - Original Sin 2 - Modding Troubleshooting Dialogue showing up as being spoken by the player.

My guess would be that you accidentally created a second dialogue box in a node, or incorrect speaker groups assigned in the conversation.

However, as Tinkerer said, it's hard to tell what the problem really is without any images to look at.