Launching the GOG copy of Divinity: Original Sin II - Definitive Edition through either the support tool ("Divinity - Original Sin 2\bin\SupportTool.exe") or the game executable directly ("Divinity - Original Sin 2\DefEd\bin"), has the game instantly close in the middle of the intro videos.
The only time it doesn't do this is if the game is launched through the GOG Galaxy client.